Abnormal gravitational field

Abnormal gravitational field. Abnormal Earth crust and upper mantle thickness.

Earth gravitational field or field of gravity force – is a force field caused by Earth gravity and centrifugal force as a result of the Earth axial rotation. It is conventionally divided into abnormal and basic-normal parts, calculated according to the distribution formulae of acceleration of normal gravity. Abnormal part of field is considerably smaller in magnitude, has complicated structure and reflects Earth form characteristics and its subsoil inhomogeneity. On a map abnormal gravitational field structure is shown by the similar size lines of its values, which are called isoanomalous lines.

Abnormal gravitational field changes in wide ranges in connection with great diversity of Earth crust and upper mantle material thickness distribution along the lateral when natural gradient stratified increasing at the same time with depth; in some regions thickness inhomogenuities take place in the upper mantle also. Gravitational field morphology and intensity visually in the first place reflect thickness distribution characteristics in the subsurface Earth crust part.

In the Western Ukraine (Precarpathian bending), where sedimentary strata is thick and bounder crust-mantle (or the Mokhorovichich discontinuity) is immersed greatly, minimal magnitude of the field in Bouguer reduction (up to -100mGal). To the West from Carpathians Moho discontinuity rises sharply, and field becomes positive (up to +30 mGal). In the north-western part of the territory, where the sediment thickness reaches 1-3 km, the field is weakly negative (about -10-20mGal).

Central part of Ukraine is situated on the Ukrainian Shield. Field level there is weakly positive. And granitic massifs are characterized by the subzero field (except anomaly in -30mGal over the massif in the region of Novoukrainka-Kirovohrad), and basic materials and granulites are characterized by positive field magnitude, the most intensive of which is (higher than +60 mGal) are observed in the region of Golovanivsk. On the south East of the Shield great positive anomalies are made by the ferruginous structures in the regions of Kryvyi Rih, Dnipropetrovs’k, Nikopol’, Zaporizhzhia, Melitopol’, Mariupol’.
In the Eastern part of Ukraine the Dniprovs’ko-Donets’kyi avlakogene (DDA) is situated. The field there depends on correlation of sedimentary strata effects and basic Devonian material implanted along the axis of the avlakogene. In general, between the depressions due to the sedimentary strata thickness decreasing lifting of the Moho discontinuity is observed. High field is observed in Donbass (higher than +40mGal), where thick sedimentary strata materials are very metamorphized and have high thickness. From the North DDA is characterized by the minimal field, that is caused by light sedimentary strata, and the local intensive minimums in the regions of Sieverodonets’k (-40 mGal), Svatove, Shevchenkove, Okhtyrka are caused by the sole material low thickness.
On the South, in Crimea, very high field is observed, which maximum (over than +150mGal) is situated in the Crimean Mountains. Earth crust there usually has the basic structure and there might be ultrabasic materials.
In the tectonically active structures (Carpathian, Donbass, Crimea) in gravitational field effects of mantle material thickness decrease, caused by high temperature influence.

Gravity isoanomalies (mGal)

The connection between structure characteristics and Earth crust substantial structure (upper mantle in some regions) and gravitational field is in most cases inverse. That is why features of abnormal Earth crust and upper mantle thickness distribution were discovered only with the help of methodology and technology of gradient stratified three-dimensional deep structure gravitational modeling worked out in Ukraine, which is based on rapid openings, correlation dependences r=f (Vp) for crystalline materials, which are based on experiments under PT conditions of deep structures subject to material substantial structure specific amendments, studying of theoretical models of different types of blocks, modern software.
Due to that, Earth crust and upper mantle abnormal thickness areas are singled out and regularities in its distribution were established. It was found out that due to isostatic compensation tendency of the separate blocks and its groups heavier blocks has immersing of the Earth crust bottom, and the lighter ones – lifting of the Moho surface. That is, on the Ukrainian Shield the Golovanivs’k structure, separate blocks on Volhynia-Podolya and in other regions have Earth crust raised thickness when bending, and granitoid blocks (Kirovohrad, Korosten’ and others) are characterized by the material lightened thickness and lifting of the Moho bounder.
By results of gravitational modeling areas of upper mantle materials with raised thickness under the DDA, Crimea, Precarpathian, and in Transcarpathian region- area of upper mantle material with lightened thickness are predicted.

Authors: V. I. Starostenko, S.S Krasovsky

Abnormal magnetic field. Regional magnetic anomalies

During the last years the abnormal magnetic field has been successfully used for the construction of non-uniformly scaled solid models, the geological environment, which is also an integral part of the estimation of perspectivity of geological structures on different minerals.

The magnetic or geomagnetic field, is a force field caused by electromagnetic processes in a kernel of the Earth (main, or a normal field), in the top layers of the ionosphere (a variation of a geomagnetic field) and magnetisation of earth crust materials. The former factor forms an abnormal magnetic field which displays presence of materials with different concentration of magnetic minerals in earth crust. The most abnormal magnetic field on the territory of Ukraine is represented on NAU map "the Abnormal magnetic field". It is received by an exception of the variations connected with ionospheric processes, and, a so-called, normal field from intensity of the general geomagnetic field. The normal field has no exact analytical image and consequently has several approximating models, one of which is represented on NAU map "the Normal magnetic field".

The abnormal magnetic field, which is found on the territory of Ukraine is differentiated greatly and consists of the regional and local components, which differ in the lateral dimensions of anomalies and the depth of their sources. Regional field component, represented on the map "Regional magnetic anomalies" is conditioned by the heterogeneity of structure of the lower part of earth crust and a relief of the magnetoactive layer bottom, which can be identified with an earth crust bottom (Мохоровічич section) or with an isothermal surface of Curie temperature magnetite as the main carrier of materials' magnetism. It displays regional features of the big geostructures, and particularly of separate blocks of the Ukrainian sheet and the imposed trenches of a platform part of territory, border of the East European platform and heterogeneity of earth crust within Mountainous Crimea and Carpathians. Local component of an abnormal magnetic field is influence of magnetised materials of the top part of the crust and displays its composition and a structure. Use of local magnetic anomalies in the search purposes has begun in Ukraine more than 100 years ago with opening and the further research of Krivorozhsky iron-ore deposit. Now this component of a magnetic field is used as one of the reliable information sources during geological mapping of materials, studying of fold and explosive tectonics, tectonic zoning, and together with the regional component and other geophysical data - for studying of correlations between near-surface and deep lithospheric structures. The former is an important factor in the development of searching criteria for the different types of minerals, including oil-and-gas. From this point of view special value acquires tracing according to abnormal magnetic field data of the so-called through faults and a trance of regional tectonic zones, which are often enough zones of activization and concentration of minerals.

During the last years the abnormal magnetic field has been successfully used for the construction of non-uniformly scaled solid models, the geological environment, which is also an integral part of the estimation of perspectivity of geological structures on different minerals.

Conclusions

General conclusions concerning conducted research.

1. The construction technique of the maps, displaying abnormal magnetic field (?Т)а, its regional (?Т)а.reg and local (?Т)а.loc. components and module T was developed.
2. The new estimation criterion of the terrestrial magnetic field storminess was offered, which can be used in the study of the geomagnetic field's secular course and its ecological aspect.
3. Maps of abnormal magnetic field (?Т)а, its regional (?Т)а.reg and local (?Т)а.loc. components, module T, storminess ?D and ecological storminess ?Decol foer the territory of Ukrain were worked out.
4. Maps of the geomagnetic field’s regional component (?Т)а.reg., storminess ?D and ecological storminess ?Decol for the East-European platform were created.

Natural conditions and natural resources. Geophysical fields

Physical fields that were caused or changed with planet natural environment called geophysical fields (GF). GF change and distribution in time and space depend on resources availability and power and on natural environment characteristics structure and its dynamics under the influence of natural and anthropogenic factors as well. It is important to know the present condition and change nature of GF for understanding of natural processes, that influence the people’s life and country economics, for long-timed socio-economic planning, rational earth usage, task-oriented minerals seeking and dangerous processes prediction.

Gravitational field of the Earth or field of gravity force is the field caused by gravity force and centrifugal force, that was entailed Earth axial rotation. It is conventionally divided into abnormal and normal. Abnormal gravitational field (AGF) represents Earth form and its subsoil structure characteristics. AGF changes in the wide range on the territory of Ukraine, thatia connected with characteristics of Earth crust material and upper mantle thickness. On the atlas map the AGF distribution is showed with the lines of the similar values of its quantity, that is called isoanomaly.

On the base of gravitational modeling of the schistose inhomogeneous three dimensional deep structures with the usage of data about abnormal gravitational field, deep seismic sounding data (DSS), experimental correlate dependences between specific thickness and seismic-wave propagation under the conditions of different temperatures and tenses considering material constitution amendments was created a map of abnormal Earth crust and upper mantle thickness. Due to the tendency to isostatic equilibrium of separate blocks and its complexes the bottom of the Earth crust immerses under heavier blocks and rises under lighter ones.

Thermal field also gives the important information about structure and dynamics of our planet. Thermal condition of the Earth crust is characterized by thermal flow thickness that comes from the Earth subsoil and dissipates from its surface and by temperature change depending on depth.

The main part in formation of the thermal flow plays: the long-living radioelements’ (uranium, thorium, potassium) break-up energy, the maximal concentration of which is observed in the Earth crust materials, primary Earth energy and the energy of the physicochemical processes that take place in its subsoil. The important part in positive geothermal anomalies formation plays also thermal conduction conditions that significantly change depending on depth and according to lateral. The leading part in positive geothermal anomalies formation plays active tectonic and magmatic processes that is attended by release of the great amount of heat.

Thermal flow thickness – is a quantity of heat that is released from subsoil to surface per time unit on area unit. It is measured in mW/m2 and is defined as the result of multiplication of the geothermal gradient in the definite depth interval and the material thermal conductivity of this interval. On the territory of Ukraine the thermal flow thickness changes from 25-30 mW/m2 to 100-110 mW/m2. Temperatures on the depth of 1 km changes from 20 to 70oC, and on the depth of 3 km – from 40 to 135oС. Thermal flow distribution is closely connected with geological development characteristics or the regions and its tectonics.

Deep thermal flow (DTF) is defined as observed thermal flow corrected considering numerous nearsurface influences: paleoclimate, groundwater move with vertical component, geological structures, that cause out-of-level bedding of the distribution surfaces with different thermal conductivity, young overthrusts, conglomeration of young sediments etc. DTF map shows the distribution of its background (35-50 mW/m2) and abnormal (60-130mW/m2) values on the territory of Ukraine.

Earth thermal energy is a geoenergy resource. The map given in the atlas (map of geoenergy resources thickness in tones of conditional fuel on square meter that can be mined with water geocirculate system with the carrier temperature not less than 60oC and its returning to the subsoil with T ~ 20oC) was made on the base of DTF data. General geoenergy resources of Ukraine (present time defined) approximately 20 times exceed all the reserves of fuel minerals on its territory. They reach 10 t c.f/m2 on some areas, that exceeds reserves that can be mined from the big oil or gas field. Geoenergy resources suitable for practical usage by steam getting (electric power) without additional heating are investigated only in Transcarpathia and not very limited territories of Crimea.
Magnetic or geomagnetic field is geophysical force field caused by electromagnetic processes in the Earth core (main or normal field), in upper ionosphere (geomagnetic field variation) and Earth crust material magnetization. Last factor forms abnormal magnetic field that shows availability of the materials with different concentration of magnetic minerals in the Earth crust. It is defined by excluding normal field intensity and its variations from general geomagnetic field intensity. Normal field does not have exact analytical image. Several approximate models are used for its description, one of which is in the atlas.

Abnormal magnetic field of the territory of Ukraine is very differentiated and consist of regional and local components which differ by diametrical anomaly sizes and source placing depth.

Regional field component showed on the map “Long waved magnetic anomalies” is provided by inhomogeneous structure of the Earth crust lower part and the relief of magnetoactive layer bottom, that can be equaled to Earth crust bottom (Mokhorovichich discontinuity) or to isothermal surface Curie temperature magnetite – the main carrier of materials’ magnetism. It reflects regional characteristics of the big geostructure.

Local abnormal field component is formed under the influence of magnetized materials of upper Earth crust part and represents its structure. This magnetic field component is used as one of the important information sources for geological material mapping, fold and disjunctive tectonics, tectonic zoning study and in complex with regional component and other geophysical data – for studying surface and deep lithosphere structure correlations, for making non-uniformly scaled three-dimensional models of geological environment, that are used when geologize geological structures to find different materials.

Magnetotelluric Earth field is a natural electromagnetic field, caused current system. This field is one of the important source of knowledge about present geological structure, tectonic processes, geodynamics and fluid rate of Earth crust and mantle. Material electrical properties are closely connected with temperature and fluid subsoil rates, mineral chemical composition, consisting of C, S, Fe and other metals, juvenile waters mineralization level, available melt of crust and mantle materials etc. On the base of observed magnetotelluric field analysis using the methods of film and two-dimensional finite difference electromagnetic fields modeling the given in atlas maps “Earth crust electroconductivity” and “Upper mantle electroconducivity” in the siemens (S) – units of conductivity were made. Electroconductivity anomalies are distinguished above “normal” generalized Eastern Europe geoelectrical section, that characterized by specific electric resistance (in ohm.m): 1000, 600, 250, 100, 50, 20, 10, 5, 1, 0.1 – in the geological environment layers with power (in km): 160, 40, 50, 70, 80, 100, 100, 160, 200, ?. Value of longitudinal electroconductivity of the environment film was taken as 10cm.

For studying deep Earth structure: geometry and main tectonic bounder location, physical parameters distribution of geological environment etc – another type of GF is used widely – seismic field. It is observed in the form of mechanical oscillations on the soil surface or in mines, caves, adits, boreholes. Oscillations are generated by seismic waves (longitudinal, diametrical, surface, channel), that propagate from the source fading, reflecting, refracting and reradiating in other types on geological environment inhomogeneities. Depending on source seismic field can be natural or anthropogenic.

Studying of anthropogenic seismic fields that were by special explosions or by Vibroseis generated and observed along geologic profiles, allowed getting unique data about Earth structure, that are used for minerals searching and solving other geological-geophysical problems. There are Earth crust and lithosphere sections through the main tectonic structures on the territory of Ukraine in the atlas.

1. Observations on the deep seismic sounding (DSS) geotraverse “Holovanivs’k – Kirovohrad - Taganrog”, that crosses in latitudinal way Eastern and Central parts of Ukrainian board, were made according to the uninterrupted profiling method using the mutually connected travel- time curves of the main waves. This model shows velocity properties and deep structure of the Archean-Proterozoic parts of the board.
2. Geotraverse “Black Sea – Baltic Sea” on the territory of Ukraine has the 900 km length. It crosses Paleozoic Skythian plate and Precambrian Ukrainian board. Velocity model was made on the base of two-dimensional figure wave field modeling, that was taken by DSS method.
3. DSS profile “Poltava- Sverdlovsk” goes along Dnipro-Donets’k avlakogen. DSS results was taken and interpreted by the big staff of Ukrainian geologists and geophysicians.
4. Deep seismic researches on the profile “Berehovo – Dolyna – Vyshnevets’ – Shepetivka - Chernigiv” showed the tectonic structure of different age and genesis: Transcarpathian Mesozoic – Palaeogene bending, Carpathia, that are one of the main European Alpine orogenes and Archean-earlyProterozoic Ukrainian board.
5. DSS profile “Putyvl’-Kryvyi Rih” join the ultradeep well UDW-8 and 9. In its Southern part it goes along Kryvoriz’ko-Kremenchutc’ka submedidianal early protherozoic protogeosyncline, and in the Northern – obliquely crosses Dnipro-Donets’k late proterozoic- Devon paleorift north-western extent.
6. On the territory of Ukraine great amount of seismic profiling were done (over 10 th km) for studying Earth crust and lithosphere structure. A map of Mokhorovichich surface was made in the atlas according to these data. The word “surface” is conventional, as actually it is powerful transition zone, that divide Earth crust from the upper mantle, that is characterized by complicated structure, alternation of thin layers with higher and lower seismic waves velocities.

On the territory of Ukraine Earth crust thickness changes in wide ranges from 25 to 65 km. Maximal crust thickness fixes under the Carpathia (65 km), Mountain Crimea (up to 60 km), jn the Ukrainian board (Odessa-Yadliv, Kryvyi Rih-Krupets’k, Orikhovo-Pavlohrad early Protherozoic geosyncline zones – 50-60 km). Minimal Earth crust thickness is observed in the Transcarpathian bending region (25 km), under Dnipro-Donets’k avlacogene (30-35 km), on the Ukrainian board, in the Zaporizhzhya middle massif region (25-30 km), Kirovohrad protoplatform block region (35 km) and on the water area of Black Sea depression (25-30 km).

Natural seismic fields caused by the local and strong distant earthquake foci, must be taken into account because of their dangerousness when accommodations, important buildings, objects at ecological and anthropogeneous risk are built. The cause of earthquakes is the present geological structure tectonic activity. Distribution of different magnitude earthquakes on the given territory in time and dimension is called seismicity.

On the territory of Ukraine the high seismicity level is observed mainly on the territory or Carpathia and Crimea-black Sea region.

Seismicity of the Carpathia region depends on the earthquakes with epicenters in Transcarpathia, Carpathia and on the adjacent territory of Poland, Slovakia, Hungary, Romania. The most active is Transcarpathia.
On the Western regions territory (from 18th century and to the present time) earthquakes are characterized mainly by foci depth (h) 2-10 km and magnitudes (M)< 5,5. due to the small depth these earthquakes caused local effects on the soil surface with intensity up to 7-8 points on the MSK-64 scale. Similar fluctuations are felt on the Transcarpathia from deeper (h=35 km) and bigger (M=6.8) earthquakes with epicenters in Romania at the ~60 km from Ukrainian bounder. the biggest at the adjacent territories of the Precarpathia earthquake was in the 1875 year in the Lvivs’ka region. It has magnitude M=5.3, focus depth h=19 km and was felt in the epicenter with the intensity 6 points. In Chernivtsi intensity reached 3 points.

The territory of Ukraine is influenced by the subcutaneous earthquakes from Vrancea zone in Romania. Earthquake foci are placed in the mantle on the depths from 80 to 190 km. Maximal magnitudes reached 7.6. Due to big depths of the foci and magnitudes earthquakes from the Vrancea are felt on the huge territory: from Greece on the south to Finland on the north. There are earthquake foci from the Vrancea zone from 11th century with magnitudes higher than 3.5 on the epicenter map. For the last two centuries isoseims for the strongest earthquakes were defined.

Seismicity of the Crimea-Black sea region is defined by the earthquake epicenters, placed in the Black Sea water area near the Southern Coast of Crimea. They are characterized by the highest in the Ukraine magnitudes (M=6.8). On the epicenter map earthquake are represented with M>2 from the first century to the present time. On the lower part of Crimea and Sea of Azov waters area earthquake foci with M>1 are shown.

On the platform part of Ukraine only several local earthquakes are known. Their foci were in the Earth crust range, and to it, seismic effect had local character. Seismic swing intensity in the epicenter reached 6-7 point. Earthquake with intensity of 6 points on the MSK-64 scale that took place on January 3, 2002, near the village Mykulyntsi Ternopils’ka region and aftershock trail are the evidence of seismic activity availability of the platform tectonic structures on the territory of Ukraine.

Danger level, which can be caused by earthquakes, is displayed on the maps of general seismic zoning (GSZ) in the numbers of MSK-64 macroseismic scale. These maps are used in long-term social-economic planning, rational land use, acceptance of administrative and technical decisions concerning maintenance of existing constructions' stable operation and placing of the new ones (HPS, APS, pipelines, etc.). In Ukrainian seismic areas design-survey and construction works are regulated through three probabilistic ЗСР-2004 maps, marked as A, B and C. They represent intensity values of seismic shakings, which can become evident once in 500, 1000 and 5000 years accordingly, or, in other words, may be exceeded with probability of 10 %, 5 % and 1 % in the next 50 years.
Maps of seismic zoning (SZ) display a predicted increase in seismic numbers on different territory lots, according to the one, presented on GSZ map. Increases may be positive or negative, depending on the local soil conditions, relief and presence of tectonic failures. Engineering-geological researches data, macroseismic inspections of earthquakes consequences data, tool observation over the earthquakes' seismic fields, explosions, natural and technogenic microseisms are used while creating SZ maps. SZ maps are used for planning of population aggregates' development, maintenance of existing constructions' stable operation and designing of the new ones.
The maps of geophysical fields represented in the atlas and the maps and schemes, created on the basis of their interpretation, which display depth of the lithosphere structure, dynamics of tectonic structures, the danger, connected with earthquakes, creep movements, shifts, subsidences, etc., is an important tool for the preception of a deep planet structure, purposeful search of minerals, protection of the population, habitation and important constructions from dangerous endogenous processes and the secondary engineering-geological phenomena, connected with them.

2005

2006

Nonmagnetic Deep Blocks of Earth Crust in connection with the Nodes of Traversal of Transemegablock Crustmantle Magmoactive zones

Edges of the deep magnetic blocks of the earth crust in association with section knots of transmegablock crust-mantle structurally-deformational (magmoactive) zones are perspective in kimberlite magmatism.

Non-magnetic deep blocks of the earth crust in association with section knots of transmegablock crust-mantle structurally-deformational (magmoactive) zones are perspective in kimberlite-lamproite magmatism.

Genetic and structural-genetic connections between abnormal magnetic field of the earth and its oil-and-gas content are substantiated.

On the basis of the developed maps of regional and local magnetic anomalies of the oil-and-gas basins of Ukraine, locations of the basic deep oil-and-gas monitoring fractures and fractures and oil-and-gas providing channels are substantiated, and the ways of hydrocarbons migration can be connected with it.

Petromagnetic Types of Earth Crust

By the magmatism type, size of magnetisation and yhe lithosphere structure, four petromagnetic earth crust types are singled out.

The most widespread mafic and sialmafic types, which are characterised by the basic magmatism and high magnetisation values, are considered to be the structures of extension modes. Areas of primordial continental crust consolidations, rifts (paleorifts) and zones of oceanic and continental lithosphere articulation can be analogues of such structures.

Initial magmatism of the basic structure and formation of the magnetic sources is considered to date back to early stages of the large tectonomagmatic cycles, which coincide in the time relation with the periods of maximum dislocations of the Ukrainian board in width or its maximum turns.

Regions' perspectivity in minerals of magmatic, hydrothermal and pegmatite types is defined by the through lithospere structures together with corresponding conditions in earth crust.

Results of 3D Analysis of Magnetic Model of Earth Crust

3D Earth crust magnetic models with other geological-geophysical data in connection with tectonics, magmatism, metallogenic specialisation and minerals prognostication were analysed.

Magmatic formations of the basic and ultrabasic structure of pre-platform development stage of Ukrainian board, which are drawn off on the surface of crystal base, are situated mainly over deep blocks (or their edges) of the Earth crust with the raised magnetisation values;

Reduction of average magnetisation value of the materials with basic and ultrabasic structure along with the reduction of their formation age is discovered, and the maximum magnetisation of crust bottoms of archaic Podolsky, Buzhsky, and partially Serednyoprydniprovsky megablocks and the West Priazovsky block, its smaller intensity in the Volynsky megablock and practically not magnetic bottom crust of the platform activization areas is connected with it.

Black Sea in Bloom

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This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of biological activity currently ongoing. The brownish pixels in the Azov are probably sediments carried in from high waters upstream. This scene was acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on May 4, 2002.

According to the Black Sea Environment Programme’s Marine Hydrophysical Institute, the Black Sea is “one of the marine areas of the world most damaged by human activities.” The coastal zone around these Eastern European inland water bodies is densely populated—supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west.

Because it is isolated from the world’s oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea’s waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality.

Scientists from each of the Black Sea’s bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem. Working with a spirit of placing more emphasis on joint ownership of the Black Sea’s resources, and less emphasis on blame, it is hoped that the cooperating countries can strike an effective balance between both enjoying and preserving the Black Sea.

Image courtesy the SeaWiFS Project, NASA GSFC, and ORBIMAGE.

EO Natural Hazards: Stressed Crops in Ukraine and Russia

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Image Acquired:  May 08, 2006

Stressed Crops in Ukraine and Russia
Under the one-two punch of a dry fall and a frigid winter, winter crops in Ukraine were in poor condition in April and May 2006. This vegetation anomaly (difference from normal) image was created from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Widespread brown indicates that plants throughout the region had grown less compared to the average growth for 2000-2005. The Foreign Agricultural Service, a division of the U.S. Department of Agriculture, estimated that only 10 metric tons of winter wheat, the primary crop growing here, would be harvested in July and August. That figure was down about 46 percent from the 18.7 metric tons harvested in 2005.

Why were winter crops in such rough shape? The biggest reason is drought. From August to October or November, depending on the location, little rain fell over the Ukrainian fields where winter grains were being planted, said the Foreign Agricultural Service. In Ukraine, roughly 42 million hectares of the total 60 million hectares is devoted to agriculture, and winter wheat and barley are among the most important crops. Planted in the fall, winter grains typically develop strong roots before going into dormancy with the onset of winter. During the winter, the crop is protected from the killing cold by an insulating layer of snow, and when the snow melts, the grain continues to grow until it is harvested in July and August. In 2005, the drought delayed planting, so the plants did not have time to develop strong root systems.

And then the cold hit. An unusual deep freeze gripped Eastern Europe in mid-January. Though little of the wheat crop was damaged, winter barely and rape seed were. The widespread impact of drought and cold is clear from the negative vegetation anomaly shown above.

All crop information cited in this caption is from the Foreign Agricultural Service. Links to the most recent crop report and general information about Ukrainian agriculture are provided below.

Further Reading:

• Ukraine: Wheat Yield Forecast to Drop Due to Severe Fall Drought, a commodity intelligence report released by the USDA’s Foreign Agricultural Service.
• Ukraine: Agricultural Overview from the Production Estimates and Crop Assessment Division of the USDA’s Foreign Agricultural Service.

NASA image created by Jesse Allen, Earth Observatory, using data provided by Inbal Reshef as part of the Global Agricultural Monitoring Project between NASA, USDA’s Foreign Agricultural Service (FAS), and the University of Maryland.

EO Newsroom: New Images - Chernobyl, Ukraine

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Eighteen years ago, on April 26, 1986, the world’s worst nuclear power accident occurred at the Chernobyl Nuclear Power Plant near the Ukrainian-Belarus border. Toxic radionuclides like Cs137 and Sr90 contaminated an area of 155,000 square kilometers in what is today Belarus, Ukraine and Russia. Hundreds of thousands of people were killed, sickened from radiation-induced illnesses, or resettled to uncontaminated land.

Today, the immediate area remains off limits to humans. The plant was permanently closed in 2000. The surrounding agricultural land has been abandoned, and the two nearby towns (Pripyat to the north and Chernobyl to the south) where plant workers lived are largely ghost towns. Instead of people, abundant wildlife—packs of wolves, deer, and birds—roam and live near Chernobyl.

This image, taken seven years ago from the Russian Mir spacecraft, shows Chernobyl and the surrounding countryside. The power plant is situated on the northwest end of a cooling pond on the Pripyat River, which flows into the Dnepr River just 80 miles north of Kiev. The main features visible in the image are the massive concrete dams and levees that were constructed to contain elements of the power plant and prevent contaminated runoff from entering the local streams. The cooling water canals leading to the pond, and the levees in the middle of the pond that channeled the water circulation can also be seen. The darker green regions are forests and the light green areas are cleared land used for agriculture.

Links:

• USGS Earthshots: Chernoby
• The United Nations and Chernobyl

Image NM23-745-116 was taken April 27, 1997, from the Russian Mir Space Station with a Hasselblad medium format camera equipped with a 250-mm lens and is provided by the Earth Observations Laboratory, Johnson Space Center. The NASA-Mir program was the first phase of the International Space Station Program, which now supports the Earth Observations Laboratory. The program trains astronauts to take pictures of Earth that are of value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth.

EO Newsroom: New Images - Icy Spring Decimates Winter Crops in Ukraine

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Severe ice crusting during February and March 2003 smothered both winter grains and alfalfa fields throughout central and southern Ukraine.

Approximately 50 percent of Ukraine's winter wheat perished over the winter, including nearly 90 percent in the Dnipropetrovsk region, which is one of Ukraine’s top grain producing regions. The ice also destroyed 90 percent of the barley crop, and 30 percent of the rye crop.

The difference between a normal year of winter crop production and this spring’s devastating losses is shown in the pair of images of above, captured on April 17, 2003 (top), and April 21, 2002 (bottom), by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra spacecraft. The false-color composite shows vegetation as green, bare ground as brownish-red, clouds as light blue, and water as black or dark blue.

Bare soil dominates this year’s image, with most of the Ukraine (center), southwestern Russia (right), and Moldova (southwest of Ukraine) swathed in deep reddish brown. Slim ribbons of green vegetation line the small rivers feeding into the Dnieper River (center), and in the upper left corner, the Pripet Marshes appear green as well. At bottom center is the northern part of the Black Sea, with the Sea of Azov to the northeast. The Russian landscape to the east of the Sea of Azov had dramatically less vegetation this spring than last.

According to statistics from the USDA Foreign Agricultural Service, this year’s winterkill in Ukraine was the worst in recent history. The wheat production estimate of 9.5 million tons put out in May by the Production Estimates and Crop Assessment Division (PECAD) of the Foreign Agricultural Service was the lowest in 40 years. Read more about the crop damage in an article by PECAD.

Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC.

EO Newsroom: New Images - Kiev, Ukraine

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Kiev (also spelled Kyiv) is the capital of Ukraine, the second largest country in Europe (second only to Russia and slightly larger than France). The city’s history has long been entwined with Russia’s. In the region’s early history, Kiev was the capital city of a state that encompassed much of the surrounding lands. Invaded by the Mongols in the 13th century, Kiev fell from primacy, but rebuilt itself and remained a major city power for centuries. It became the capital of the newly independent Ukraine in 1991 when the country declared independence from the Soviet Union.

This natural-color scene of Kiev was acquired by the Landsat 7 satellite’s Enhanced Thematic Mapper Plus (ETM+) on September 14, 2001. The city landscape is dominated by high-rise apartment buildings, a network of wide boulevards, public monuments, and city parks. In this image, green indicates vegetation, blue indicates water, and beige and gray indicate buildings and roads. The geometric shapes of agricultural land show up in the lower left corner of the image, while dark green forests dominate the upper left and the right margin.

Kiev is built on the banks of the Dnieper River, which runs north to south through the center of Ukraine and into the Black Sea. The curving river meanders through the city, and once outside, it widens to a width of 1.6 kilometers (1 mile). Farther downstream, however, it passes through a rocky plateau, changing to a series of rapids that provide hydroelectric power. A large hydroelectric dam just north of the city controls the flow of the river’s water and provides some of the city’s electrical power, though much more power comes from the famous and controversial Chernobyl nuclear power plant farther north.

NASA image created by Jesse Allen, Earth Observatory, using data obtained from the University of Maryland’s Global Land Cover Facility.

EO Newsroom: New Images - Kyiv, Ukraine (2)

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Last week, the International Space Station Expedition 8 crew took a series of images of the Ukrainian city of Kyiv (Kiev) on a reservoir on the Dnipro (Dnieper) River. Kyiv is the capital of Ukraine and home to nearly 3 million people.

Kyiv is rich in the history of western civilization. It was a trade center on the Baltic-Black Sea route in the 11th and 12th centuries, and one of the major cities in the Christian world, until Mongol invaders destroyed the city in 1240. Some of the 11th-century cathedrals, which contain famous artifacts, remain standing and have been restored. Throughout the Middle Ages, Kyiv suffered through different occupations, but rose to be the center of Russian Orthodox Christianity by the 1800s. This cosmopolitan city was again largely destroyed during World War II. Despite its turbulent history, many of Kyiv ’s world famous artifacts have been rebuilt, and the city is prominent as a cultural center.

Image ISS008-E-20656 was taken April 4, 2004 with a Kodak DCS760 digital camera equipped with an 80 mm lens and is provided by the Earth Observations Laboratory, Johnson Space Center. The International Space Station Program supports the laboratory to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth.

Ukraine: Agricultural Overview

Ukraine agriculture has been evolving since it achieved independence in 1991, following the breakup of the Soviet Union. State and collective farms were officially dismantled in 2000. Farm property was divided among the farm workers in the form of land shares and most new shareholders leased their land back to newly-formed private agricultural associations. The sudden loss of State agricultural subsidies had an enormous effect on every aspect of Ukrainian agriculture. The contraction in livestock inventories that had begun in the late 1980's continued and intensified. Fertilizer use fell by 85 percent over a ten-year period, and grain production by 50 percent. Farms were forced to cope with fleets of aging, inefficient machinery because no funds were available for capital investment. At the same time, however, the emergence from the Soviet-style command economy enabled farmers to make increasingly market-based decisions regarding crop selection and management, which contributed to increased efficiency in both the livestock and crop-production sectors. Difficulty in obtaining credit, especially large, long-term loans, remains a significant problem for many farms.

Agricultural Land Area and Major Crops

The climate of Ukraine is roughly similar to that of Kansas: slightly drier and cooler during the summer and colder and wetter during the winter, but close enough for comparison. The weather is suitable for both winter and spring crops. Average annual precipitation in Ukraine is approximately 600 millimeters (24 inches), including roughly 350 millimeters during the growing season (April through October). Amounts are typically higher in western and central Ukraine and lower in the south and east.

Of Ukraine's total land area of 60 million hectares, roughly 42 million is classified as agricultural land, which includes cultivated land (grains, technical crops, forages, potatoes and vegetables, and fallow), gardens, orchards, vineyards, and permanent meadows and pastures. Winter wheat, spring barley, and corn are the country's main grain crops. Sunflowers and sugar beets the main technical, or industrial, crops. Agricultural land use has shifted significantly since Ukraine declared independence from the Soviet Union in 1991. Between 1991 and 2000, sown area dropped by about 5 percent, from 32.0 million hectares to 30.4 million, and area decreased for almost every category of crop except for technical crops (specifically sunflowers). Forage-crop area plunged by nearly 40 percent, concurrent with a steep slide in livestock inventories and feed demand.

Wheat is grown throughout the country, but central and south-central Ukraine are the key production zones. About 95 percent of Ukraine wheat is winter wheat, planted in the fall and harvested during July and August of the following year. On the average, approximately 15 percent of fall-planted crops fail to survive the winter. The amount of winterkill varies widely from year to year, from 2 percent in 1990 to a staggering 65 percent in 2003, when a persistent ice crust smothered the crop. Wheat yield declined during the 1990's following the breakup of the Soviet Union and the loss of heavy State subsidies for agriculture. Farms struggled with cash shortages, and the use of fertilizer and plant-protection chemicals plummeted. Due to a combination of favorable weather and a modest but steady improvement in the financial condition of many farms, wheat production has rebounded in recent years (except for the disastrous 2003/04 crop which fell victim to unusually severe winter weather). Ukraine produces chiefly hard red winter wheat (bread wheat), and in a typical year roughly 80 percent of domestic wheat output is considered milling quality, by Ukrainian standards. Feed consumption of wheat dropped sharply during the 1990's, from over 12 million tons to less than 5 million. Meanwhile, food consumption has remained steady at around 10 million tons.

Barley has been the top feed grain in Ukraine for most of the past ten years in terms of consumption, surpassing wheat in the early 1990's. Spring barley accounts for over 90 percent of barley area, and the main production region is eastern Ukraine. Spring barley is typically planted in April and harvested in August, and is the crop most frequently used for spring reseeding of damaged or destroyed winter-grain fields. Area is inversely related, to some degree, to winter wheat area. Winter barley is the least cold-tolerant of the winter grains, and production is limited to the extreme south. The increasing demand for malt from the brewing industry has led to a jump in malting barley production and the import of high-quality planting seed from the Czech Republic, Slovakia, Germany, and France. Consumption of barley for malting purposes has surpassed 300,000 tons, but still accounts for only 5 percent of total barley consumption.

Increased production -- specifically, three bumper harvests since 2001 -- and diminishing domestic demand for feed grains have contributed to a jump in Ukrainian wheat and barley exports. The boom in exports was fueled also by relatively low production costs and the reduction or elimination of price controls and export restrictions in 1994. Most exports go to the Middle East, North Africa, and Europe. (See attaché reports: Grain and Feed Annual, April 2004, and How is Ukrainian Grain Competitive?, August 2002.)

Corn is the third important feed grain in Ukraine. Planted area has increased despite several impediments: obsolete and inadequate harvesting equipment, high cost of production (specifically post-harvest drying expenses), and pilferage. The main production region is eastern and southern Ukraine, although precipitation amounts in some oblasts in the extreme south are too low to support corn production. Corn is typically planted in late April or early May. Harvest begins in late September and is usually nearing completion by early November. Only 25 to 50 percent of total corn area is harvested for grain; the rest is cut for silage, usually in August. (The USDA corn estimates refer to corn for grain only.) Corn is used chiefly for poultry and swine feed, and production and consumption have risen since 2000 concurrent with a rebound in poultry inventories. Russia and Belarus are the chief destinations for Ukrainian corn exports.

Sunflowerseed is Ukraine's chief oilseed crop. Production is concentrated in the southern and eastern oblasts. Sunflowers are typically planted in April and harvested from mid-September to mid-October. Because of a combination of high price, relatively low cost of production, and traditionally high demand, sunflowerseed has become one of the most consistently profitable crops. (See Sunflowerseed Production in Russia and Ukraine, June 2004.) Its high profitability fueled a significant expansion in planted area beginning in the late 1990's. Many farmers in Ukraine abandoned the traditional crop-rotation practices recommended by agricultural officials which called for planting sunflowers no more than once every seven years in the same field. The aim of the 1-in-7 rotation is to prevent soil-borne fungal diseases and reduce the depletion of soil moisture and fertility. (Because of their deep rooting system, sunflowers reportedly extract higher amounts of water and nutrients from the soil than do other crops in the rotation.)

Sugar beets are grown primarily in central and western Ukraine. Beets are planted in late April and early May and harvested from mid-September through the end of October. Production has been on the decline since the early 1990's due chiefly to low profitability compared to grains and sunflowerseed. Between 1994 and 2003, planted area declined by 50 percent to less than 0.8 million hectares, and production from 28.1 to 13.4 million tons. Large farms are sometimes encouraged by the local administrators to plant sugar beets not so much to make money but rather to provide a social safety net or to supplement to pensioners or farm workers. A family may be responsible for weeding a specific section of a field and the workers in turn receive 20 percent of the sugar processed from the beets harvested from its section. Sugar also frequently serves as part of farm workers’ salaries.

On private household plots, meanwhile, sugar beet area has increased. Sugar beet production requires a significant amount of hand labor and remains a viable option for small household farms with limited access to agricultural machinery. Household plots now account for approximately 25 percent of Ukrainian sugar beet output compared to only 3 percent in 1995. (See attache report: Sugar Annual, April 2004.)

Crop Rotations

Farms in Ukraine employ a variety of crop-rotation schemes, some including four or more crops, some only two. A six-year crop rotation in the winter grain region will often include two consecutive years of wheat and one season of "clean fallow," during which no crop is sown. The chief reason for including fallow in the rotation is to replenish soil-moisture reserves, and it is more widely used in southern eastern Ukraine where drought is not uncommon. A typical crop sequence might be: fallow, winter wheat, winter wheat, sunflowers, spring barley, and corn. Wheat almost always follows fallow. According to farm directors, this enables the wheat -- which is typically the priority crop -- to benefit from the reduced weed infestation. (Fields are cultivated several times during the fallow season.). Some crop rotations include several consecutive years of a forage crop. An example of such a rotation would be: fallow, two years of winter wheat, and four years of perennial forage. The perennial forage is usually alfalfa; farmers will get three to four cuttings per year, five if the crop is irrigated. In southern Ukraine, clean fallow is frequently omitted and a crop rotation will likely include sugar beets and/or sunflower, the region's chief industrial crops. A typical seven-year rotation might be: winter wheat, winter barley, sugar beets, winter wheat, winter barley, sunflowers, and corn. The vast majority of field crops, including grains, sunflowers, and sugar beets, are not irrigated. Traditionally, irrigation is used only on forage crops and vegetables. Roughly 5 percent of grains and 10 percent of potatoes, vegetables, and forage crops are irrigated.

Inputs

During the final years of the Soviet era, winter wheat was the focus of the so-called intensive technology movement, which was marked by the use of improved varieties and the increased application of fertilizer and plant-protection chemicals. Yields climbed in response to the enhanced management practices. The intensive technology program fizzled during the early 1990's, however, when the collapse of the Soviet Union marked an end to heavy State subsidies for agriculture and farms were forced to struggle with crippling cash shortages, a crumbling agricultural infrastructure, and skyrocketing fertilizer prices.

According to official statistics, the fertilizer application rate for wheat plunged from 149 kilograms per hectare in 1990 (when fertilizer was excessively and wastefully applied) to 24 kilograms in 2000. The application rate for corn dropped even more sharply. Fertilizer use has increased modestly since 2000. Rates are still significantly below recommended amounts, but wheat yields have rebounded since 2000 (except for the weather-related crop disaster of 2003) due to a combination of favorable weather and improved crop-management practices on the large agricultural enterprises.

There is no shortage of mineral fertilizers or plant-protection chemicals in Ukraine. Any inputs that a farmer needs can be obtained if the farm has money or can get credit. The high price of imported herbicides and fungicides has caused some farmers to cut back on their use, or to use less expensive and less effective domestic products. Farmers still rely to a large degree on mechanical weed control.

Obsolete Machinery and Inadequate On-Farm Storage

A chronic lack of modern harvesting equipment remains one of Ukraine’s main obstacles to increasing grain output and quality. In the late 1980's, the Ukrainian winter wheat harvest could be finished in roughly three weeks. Harvest now takes twice as long to complete, and both yield and grain quality suffer as a result of the delays. Farm managers estimate that 10 to 20 percent of the standing crop is typically lost due to outdated, inefficient machinery. Custom combining is available, but operators charge 20 to 25 percent of the crop in exchange for their services. Farmers must weigh custom-combining charges against potential harvest losses, and most choose to harvest their own grain. Another consideration for the farm director, in addition to cost, is that the harvest campaign provides work for the farm employees.

Many farmers are compelled to sell grain shortly after harvest when prices typically are lowest. One of the main reasons is a shortage of on-farm storage capacity, especially following a good harvest. This is a relic of the Soviet system, which was designed for immediate post-harvest shipment of grain to regional elevators. The need to repay short-term debts or to satisfy "payment-in-kind" arrangements is the second chief factor contributing to the untimely sale of grain (i.e., untimely from the farmer’s perspective). At harvest time many traders are offering cash for grain. Banks do not accept grain as payment, and for a farm director struggling with a heavy debt burden the lure of immediate cash is difficult to resist. The greatest obstacle to increasing on-farm grain storage and modernizing the fleet of agricultural machinery is the difficulty for many farms to obtain large, long-term loans for capital investments. (See "Credit Problems" below.)

Restructuring

The production of grain and oilseed crops is dominated by large agricultural enterprises that were established when Ukraine’s agricultural sector was restructured in April, 2000. (In contrast, nearly 90 percent of the country's vegetables and virtually all of the potatoes are grown on private household plots.) State and collective farms were dismantled and farm property was divided among the farm workers in the form of land shares. Most new shareholders leased their land back to newly-formed private agricultural associations, under the leadership of a director who was frequently, but not always, the manager of the former State farm. Consolidation of small farms into larger and more viable enterprises has been the prevailing trend, similar to what took place in Russia several years earlier. (For a brief discussion of Ukraine’s agricultural restructuring, see June 2001 report.) The conversion to a more market-oriented environment has progressed relatively well according to most observers. Many farms are succeeding, under shrewd leadership, in spite of fluctuating grain prices and constraints on the availability of credit. The transition of Ukraine's agricultural sector from a command economy to a more market-oriented system has introduced the element of fiscal responsibility, and farm managers are striving to make their enterprises as efficient as possible. Decisions on crop selection, fertilizer application, harvest method, grain storage, and all other aspects of farm management are made with an eye toward boosting farm profit. Ukraine agriculture is going through a winnowing process whereby unprofitable, usually smaller farms will either collapse or join more successful farms.

Credit Problems

Most farms are able to receive credit, but interest rates and collateral demands are high. Since many farms are already heavily in debt to banks or suppliers of fertilizer and plant-protection chemicals, and since agricultural loans are not guaranteed by the government, banks are largely unwilling to make long-term loans. Most credit is extended in the form of seasonal loans (six to ten months) used almost exclusively for the purchase of fertilizer and plant protection chemicals. Commercial interest rates typically range from 25 to 30 percent. The State provides assistance to farms by paying 50 percent of the interest on agricultural loans. Banks typically require 200 to 300 percent collateral, depending on the farm’s credit history and the risk level. Future crop usually serves as collateral, but collateral can also be offered in the form of livestock, farm machinery, or the personal property of the farm director. Under current legislation, land cannot be used as collateral. Farms' difficulty in obtaining anything other than short-term, high-interest loans places severe constraints on their ability to invest in long-term capital improvements, such as agricultural machinery or storage facilities. Using land as collateral would enable farms to receive longer-term loans, but many farm directors remain leery of the Ukrainian banking system – which is not yet as stable as in Russia – and are reluctant to risk losing their land in default. Furthermore, many agricultural enterprises are comprised of hundreds of shareholders, whose permission would need to be obtained before the farm director could use the land as collateral.

In many cases, the best option is for a farm to attract an investor who can provide market expertise, operating capital, and collateral to enable the farm to secure loans. The potential “down side” of investor arrangements, from the farmer's perspective, is that farm directors to some extent lose control of farm operations. Often the investment company, or “holding company,” insists on maintaining control over every aspect of production and essentially takes over the farm, equipment, and land. Farms are forced to enter into extended leases of five to ten years, sometimes longer, because they depend heavily on cash from the holding company.

The consensus of most observers is that already-successful farms will continue to expand as shareholders pull out of failing farms and lease their plots to stronger ones. Clearly, many farms will not survive the transition to a market economy, and high-risk farms with few liquid assets, heavy debt, bad credit history, and poor management will collapse. (See 2004, 2003, and 2002 trip reports for additional comments on the financial difficulties of Ukrainian farmers.)

Shrinking Livestock Inventories

The loss of State subsidies following the collapse of the Soviet Union in 1991 increased feed and production costs and reduced profitability for livestock enterprises. As prices for meat products increased, consumer demand declined, thus establishing a downward spiral that continued throughout the decade. Livestock inventories, and demand for forage, continued to shrink. The increasing inability of large agricultural enterprises (i.e., former State and collective farms) to maintain livestock operations, due largely to inefficient management and farms' inability to ensure sufficient feed supplied, resulted in increased dependence on private producers and household farms to satisfy demand for beef and pork. Furthermore, the involvement of investor groups (holding companies) in agricultural production has had an impact on livestock numbers. Many farms who entered agreements with investment firms killed off their herds because livestock is not quickly profitable and not as attractive to investors. Although the freefall in livestock inventories has slowed since 2000, a rapid recovery in beef production is unlikely. Cattle inventories are increasing on private household farms, which typically have two to three head of cattle per farm, but large industrial farms are shifting away from cattle and toward crop production and total cattle inventories continue to decrease. (See attaché report: Livestock Annual, August 2004.)

Global catalogues - Catalogue composed by Gytenberg and Rihter, 1904-1952

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Global catalogues - publications

1. Ganse R.A., Nelson J.B. Catalog of Significant Earthquakes, 2000 B.C.-1979. Including Quantitative Casualties and Damage.- World Data Center A for Solid Earth Geophysics, Report SE-27, Boulder, USA, 1981.

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8. Index Catalogue of Epicentres Contained in the International Seismological Summary 1936-1942. Supplement to Index Cata- loguE 1913-1930, Index Catalogue 1931-1935.- Kew Observatory, Richmond, 1953.

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13. Rothe J.P. The Seismicity of the Earth, 1953-1965.- UNESCO, 1969.

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19. The Catalogue of Earthquakes in the World, 1971,1973-1980.- In: Bulletin of Seismological Observations of Chinese Stations . Institute of Geophysics, State Seismological Bureau, Seismological Press, Beijing, China, 1974-1983.

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Other catalogues

Regional catalogues and earthquakes description - publications

Australia

1. Preliminary Earthquake Locations . IV.1982-XII.1984.- In: Preliminary Seismological Bulletin. Phase & Hipocentral Data. BMRGG, Canberra, Australia, 1982-1985.

International bulletins - publications

1. INTERNATIONAL SEISMOLOGICAL SUMMARY. INTERNATIONAL GEODETIC AND GEOPHYSICAL UNION, ASSOCIATION OF SEISMOLOGY. INTERNATIONAL SEISMOLOGICAL CENTRE

Links

• Seismological Bulletin of International Seismological Center
• Efficient seismological bulletin

National bulletins - publications