KAZAKHSTAN MONITORING SYSTEM: MERGING OPPORTUNITIES TO SOLVE GLOBAL, REGIONAL AND LOCAL TASKS

N. Belyashova

Institute of Geophysical Research, Kurchatov, Kazakhstan

Contact: belyashova@mail.ru, belayshova@igr.kz

Т1.5 – Р27

Figure 1. The map of Kazakhstan facilities for monitoring of nuclear explosions and earthquakes

Kazakhstan where the nuclear safety and non-proliferation are acknowledged as one of the main State priorities intends to move further in developing of all parts of nuclear control system, achieve substantial progress in modernization of applied technologies with replacement of equipment especially at the earliest facilities to extend the investigated territories, increase the capabilities of Kazakhstan Data Centre analysts at more active cooperation with the International and National Centers.

In Kazakhstan, the system formonitoring of nuclear explosions andearthquakes consisting of stationsnetwork (seismic, infrasound,magnetic), communication system(satellite, radio-telemetry, fiber-optic, landline, internet-channels) andData Centre – KNDC (in Almaty)covers about ~18 000 km2.

The system has been created since 1994 under support of PTS CTBTO, AFTAC, IRIS, NORSAR, GFZ, CEA and includes (Figure 1) 8 seismic arrays, 10 three-component seismic stations, 2 infrasound arrays (third will start its operation in 2015), 1 magnetic station.

● Kazakhstan infrasound network includes two infrasound arrays: IS31-Aktyubinsk (8 elements), Kurchatov (4 elements). Data of IS46-Zalesovo located on the territory of Russia are also processed. Currently, two other infrasound arrays are being constructed – in Makanchi (9-elements) and in Borovoye (4-element).

KAZAKHSTAN MONITORING SYSTEM: GENERAL VIEW

GLOBAL MONITORING REGIONAL MONITORING

LOCAL MONITORING OTHER OPPORTUNITIES

The operation of these facilities integrated into the IMS CTBTO (stations PS23, AS057, AS058, AS059, IS31), into AFTAC global system (stations PS23, KKAR, ABKAR) and IRIS (BRVK,KURK, MAKZ), into CAREMON network (stations OTUK, PDGK), and operation of potentially cooperating national facilities (KNDC seismic station, Kurchatov infrasound, Kurchatov magnetic, Borovoye large-aperture) is directed by the Institute of Geophysical Researches of the Ministry of Energy of the Republic of Kazakhstan.

● The feature of the seismic network is that it consists of seismic arrays with different number of elements, different aperture and configuration (Figure 2 and 3).

Figure 6 shows the results of events detection effectiveness at teleseismic distances by the stations of primary (PS23) and auxiliary (AS057, AS058, AS059) networks of the IMS CTBTO. The quantitative assessment of each station contribution into REB bulletin (Reviewed event bulletin) of the International Data Centre, CTBTO was implemented.

All 4 stations of Kazakhstanpart of the IMS are amongthe best. PS23 (MKAR)station yields only to twoseismic arrays near thePacific region with highseismic activity (WRA,ASAR), and arrays AS058(KURK) and AS057 (BRVK)are much more effectivethan all other stations ofthe IMS auxiliary network.

primary network stations

auxiliary network stations

Figure 6. Contribution of the International Monitoring System stations into REB bulletin compilation for 2010

The degree of PS23 (MKAR) station contribution into recording of events occurring in different regions of the world is shown in Figure 7.

Figure 7. An example of PS23 (MKAR) station participation REB

The Figure 7 shows that PS23(MKAR) records 80 and morepercent of events among thoseincluded into the REB andoccurring at regions interestingin view of nuclear explosionsmonitoring in Asia, Middle East,Africa. In these regions,minimum magnitude of therecorded events is 3,0 – 3,5.

For regional monitoring, data of more than 50 stations are used including stations of other Kazakhstan networks and neighboring countries – Kyrgyzstan, Turkmenistan, Russia, Uzbekistan (Figure 12).The regional seismic bulletin issued at KNDC contains data of 4 so called regional-telemetric arrays of Kazakhstan with aperture 3 - 4 km (PS23- МKAR, AS057-BVAR, ABKAR-Akbulak, KKAR-Karatayu). Another seismic array AS058-KURK with aperture 22.5 km is teleseismic, but it has special configuration of 9 elements improving the quality of regional monitoring.

Figure 13. Contribution of stations in compiling the CAPSSI bulletin for 2010 calculated with coefficient of data arrival

Figure14. Minimal values of events energy classes recorded by the IGR

network stations at distance of 5 degrees

Figures 13, 14 show the

effectiveness of stations

operation for regional

monitoring using the following

parameters:

• part (of unit) of the station

contribution into KNDC regional

bulletin compilation (Figure 13);

• minimum value of energy

classes of events recorded by a

station at distances 1 deg., 5

deg., (Figure 14) and 10 deg.

The most effective for regional

monitoring are three seismic

arrays: BKAR, KKAR and MKAR.

● Since 2010 the specialists from Central Asia and Kazakhstan are trained for methods of processing and interpreting of seismological data at the “International Training Centre in support of the CTBTO” (Almaty), created and supported by NORSAR at the premises of KNDC.

● KNDC has developed new techniques that allowed to improve detection, location anddiscrimination of source nature and techniques for integrated processing of seismic andinfrasound data. A series of travel-time curves (global and regional) were investigated, acombined travel-time curve for the whole range of investigated distances was created. Unusualseismic and infrasound sources were revealed and studied: glacial earthquakes in high TienShan, thunderstorms recorded by the stations, ice breakup in lakes, gas flares at Zhanazhol oildeposit in Western Kazakhstan, landslides and other.

Every year ~ 7000 earthquakes (including more than 20 with К≥9.0) and ~ 4000 industrial blasts are recorded on the territory of Kazakhstan. The largest of the events and especially those occurred in seismically calm regions are investigated in details.

In 1997 – 2000 Kazakhstan and American researchers have conducted chemical explosions at Balapan and Degelen sites of the STS (Figure 20). The main goal of the explosions was to eliminate nuclear infrastructure and calibration of IMS seismic stations. The most powerful (100 tons) were explosions in the massif Degelen-Omega-1 (1998), Omega-2 (1999), Omega-3 (2000).At “Balapan” test site in 1997 – 1998 there were 20 explosions (charge mass ranged 51,2 - 25 040 kg, laying depth – 0-630 m). The temporary stations in the near field (0.1 – 30 km) allowed to investigate influence of local geologic setting change on waves propagation, creation of travel-time curve and velocity models starting from almost zero distance.

The works conducted on analysis of localseismicity and investigation of seismic settingparameters in VVR-K reactor near field atAlmaty region of Kazakhstan have shownrelatively favorable calm seismic and tectonicconditions for basement under the reactor owingto massif of crystal granitoids under sedimentarycover (Figure 20).

Monitoring and assessment of risk of natural-inducedevents appearance on the territory of two exploiteddeposits in the west Caspian territory (Figure 21) isconducted on a continuous basis using 8 stations. From 40to 200 local events with magnitude md=0.3 – 3 arerecorded by the network per month. The createdcatalogues of events allow to study the spatial structureof micro earthquakes and its change in time owing todefinite faults, boreholes location, production horizon;connection of seismic mode parameters withcharacteristics of production and regional seismicity ofthe Caspian region.

Figure 25. Determination of “Dnepr” carrier-rocket fall place in Kazakhstan

Every year up to 800 events are

recorded and studied for Central Asia, and

up to 100 – 120 seismic events are

recorded from vicinity of Lop Nor (China), Chagay

(Pakistan), Pokharan(India) Test Sites.

Figure 15. Events at the regions of Central Asia Test Sites, 2014.

To create new maps of “General seismic zoning of RK territory” (joint works with IS) one unified catalogue includes data from different Centers for the earthquakes happened on the territory of Kazakhstan from ancient time to 2012. Inconsistent information (different types of magnitudes and classes, different years, different Centers, various scales) was reduced to one type of unified magnitude. The representativeness of contemporary recording of earthquakes with different K, including K>8.5 and magnitude mpv >3.5 was assessed.

Recording of signals by seismic and infrasound stations and assessment of source parameters at carrier rockets launch from Baykonyur space port (example – fall of Dnepr rocket, Figure 25), flight and explosion of Chelyabinsk meteorite.

● Since 2000, the International Conference “Monitoring of Nuclear Tests and its Consequences” is held in Borovoye and Kurchatov once every two years favoring regular discussion of urgent issues on developing of monitoring for nuclear tests and earthquakes and application of its data for civil tasks.

Monitoring of events on the territory of Kazakhstan

• automated ∼ 12 - 13 thousands of seismic events and ∼80 thousands of infrasound detections (real time mode)

• interactive ∼ 13 – 14 thousands of events(24 hours delay)

Monitoring of seismic events

in Central Asia region

• combined (IGR, IS networks) ∼ 15 – 17 thousands of events (delay 1.5 – 3 days)

About 50 large earthquakes of the world with M≥6.5

are recorded by Kazakhstan stations every year

The stations of CAREMON network and station AS058-KURK also make a valuable contribution.

Рисунок 16. Эпицентры событий на территории Казахстана, 2014

● KNDC possesses the archives of origin records and databases of the processing results in CSS3.0 and SEED formats with total volume about 10 Tb. The archives also include ~7000 digitized analogue records of historical nuclear explosions conducted at 5 Test Sites of the world.

Figure 23 Central Asia. The zones associated with zone of large earthquakes preparation revealed by a set of signs: 1 – zones of high attenuation of S-waves; 2 – ring structures of seismicity

The databases and KNDC archives were used for investigation of geodynamics in Central Asia and other regions, in particular, for mid-term prediction of large earthquakes with М≥6.5 based on the analysis of short-period shear waves attenuation field mostly sensitive to availability of liquid phase and ringed structures of seismicity often formed before large crust earthquakes. The method revealing the source place and magnitude of future earthquake was successfully tested on several large earthquakes from different regions of Eurasia. At Tien Shan region several places of large earthquakes preparation were revealed in the regions of Kyrgyz, Fergana ridges and other (Figure 23).

Figure 8. The records of UNE from Pokharan Test Site, 11.05.1998(left), from Chagay Test Site, 28.05.1998 (right). Chkalovo station

Figure 17. Earthquake epicenters on the territory of Kazakhstan, 2014

Figure 3.Seismic array AS058. Consists of 21

element: one three-component and 21

vertical one-component seismometer. The array

aperture is 22.5 km.

Figure 4. Spectral models of seismic noise by the IGR network stations

All arrays are located throughout the country perimeter (Figure 1) regardless seismic active zones. The stations are distinguished by high sensitivity owing to perfect seismological conditions in its location places, installation of equipment in boreholes, and joint application of three-component and one-component seismometers.

● КNDC has participated successfully in the experiments arranged by the CTBTO: SPT1 -–system-wide performance test, 2004 - 2005) and NPE09 – assessment of NDC degree of readiness.

Figure 5. Infrasound station network by the IGR

Kazakhstan stations contribution into of nuclear tests monitoring

• The nuclear tests of 11.05.1998at Pokharan Test Site (India) andof 28.05.1998 at Chagay Test Site(Pakistan) were recorded andstudied (Figure 8). The differencein explosions epicenter location ascompared to REB and USGS was 7– 12 km and 22 – 25 km,respectively.

Figure 2. Seismic array PS23. Consists of one three-component and 9 vertical one-component seismometers. The array aperture is 4 km. Stations AS057, KKAR, ABKAR

have the same configuration.

• Three UNE conducted by North Korea at Punggye-ri Test Site (2006, 2009, 2013) were

discriminated and located with high operativeness (Figure 9). The yield, magnitude of UNEand discriminants for events of this Test Site region were précised.

Figure 9. Recording of UNE at Punggye-ri Test Site in 2013 by Kazakhstan stations (on the left – location of stations regarding the Test Site, on the right – its records)

Catastrophic earthquake of 25.04.2015 in Nepal, Mw = 7.8 – 7,9 and itsaftershocks, and second earthquake 18 days later, Mw = 6.3 wererecorded by all Kazakhstan stations. The records of MKAR station wereused for REB (Figure 10).

● Origin seismic data are transferred in real and post-real time to the IDC PTS CTBTO, to US NDC,to IRIS. KNDC transfers the results of its processing in near-real time to the EMSC, to GS RAS, in Kazakhstan to the Institute of Seismology (IS), to Seismological Experience-Methodical Expedition (SEME), to the Committee of Emergency Situations (CES).

Figure 10. Fragments of REB on earthquake of 25.04.2015 in Nepal.

Monitoring of events at the

region of the nearest Test Sites

Figure 12. Stations used for KNDC regional bulletin compilation: 1-IGR seismic arrays; 2- IGR three-component stations; 3- seismic arrays of neighboring countries. Stations: 4 –CAREMON; 5 - SEME:

Figure 14. Events recorded within the Centrals Asia (Event magnitude m≥3.5)

Every year the recorded and processed events are included into the following bulletins:

• urgent location ∼ 350 - 400 events (during 10 – 15 min)

Investigation of seismicity of former Semipalatinsk Test Site (STS) territory

Figure 18. Seismic stations network at the region of test sites of the STS.

2006 – 2010

Figure 19. The earthquake epicenters at STS region

Data of permanentand field stations ofthe IGR installed atBalapan, Degelen andSary-Uzen sites(Figure 18) and dataon historicalseismicity have shownavailability ofearthquakes on theterritory of the STSand its vicinity(Figure 19).

Figure 20. Earthquake epicenters at VVR-K region. Star – location of reactor. Figures – described zones of seismicity.

Starting local monitoring at the site of VVR-K nuclear reactor with LEU fuel (Almaty region, RK)

Seismic monitoring during calibration explosions at former Semipalatinsk Test Site (STS)

Monitoring of seismicity at active deposits territory

Investigation of geodynamics of Central Asia and other regions of the world

Data of years-long seismic monitoring for the regions ofSemipalatinsk, Novaya Zemlya, Lop Nor, Nevada Test Sitesallowed to investigate (together with the IPE RAS)regularities variation in time ASn/Apn, ALg/Apg and codaenvelops as indicators of S-waves attenuation as a resultof deep fluids rise in the lithosphere due to enhancingpenetration of rocks after nuclear explosions conducted

earlier.At all investigated nuclear Test Sites the largest

variations of the attenuation field correspond to the earthcrust and upper mantle at the Test Sites regions confirmingactive migration of fluids in these regions. Figure 22 showsan example of significant increase of S-waves attenuationwith time at the trace “Lop Nor Test Site – BRVK station”.At the region of Lop Nor Test Site the fluids risecontinued even after UNE series were finished.

Study of geodynamics of large nuclear test sites territory

It was confirmed that the earthquakes happen due toactive natural tectonics and due to induced seismicity atthe places where nuclear explosions were conducted in thepast.

Figure 20. Location of stations in the near field of Omega 1,2,3 explosions

Figure 21. The map of earthquake epicenters per month

Figure 22. Lop Nor Test Site. Dependence of average values Sn/Pn on

time. Average values and standard deviations for UNE (filled signs) and

earthquakes. Horizontal risks – intervals of data averaging.

Creation of a unified earthquake catalogue for Central Asia

Within several international Projects (CASRI -Central Asia Seismic Risk Initiative), EMCA -Earthquake Model Central Asia) the unified earthquake catalogue was created for Central Asia territory from historical time to 2009. The catalogue includes instrumental and macroseismic parameters of earthquakes with magnitude ≥5 (CASRI), ≥3.5 (EMCA). The catalogue is widely used for applied tasks.

Creation of information base for new zoning of the Republicof Kazakhstan territory

Figure 24. The map of epicenters by unified catalogue of earthquakes for Central Asia

Investigation of carrier-rockets flight stages and natural phenomena

Seismograms of ABKAR (3 upper), KKAR (3 lower) stations

Records of infrasound station IS31-AktyubinskStations (triangles) and place of

rocket fall (star)

1960 1970 1980 1990 2000 2010

-0,75

-0,70

-0,65

-0,60

-0,55

-0,50

-0,45

-0,40

-0,35

-0,30

-0,25

-0,20

-0,15

годы

Sn/Pn

As a result, the noise level at all stations (Figure 4) is approaching to Peterson low-noise model.