100 Years of Paper Seismograms from Denmark and Greenland, 1907–2008

2022 ◽  
Author(s):  
Trine Dahl-Jensen ◽  
Lif Lund Jacobsen ◽  
Ann-Sophie Graulund Sølund ◽  
Tine B. Larsen ◽  
Peter H. Voss
Keyword(s):  
World Wide ◽  
Nuclear Explosion ◽  
Historical Context ◽  
Nuclear Test ◽  
Novaya Zemlya ◽  
National Archives ◽  
Local Earthquake ◽  
Seismographic Network ◽  
Case Stories

Abstract The paper seismograms from 100 years of observations in Denmark and Greenland has since October 2021 been made available through the Danish National Archives. Five case stories illustrate the quality and variation of the seismograms, and the historical context of operation of the stations. (1) The earliest recorded earthquake in the archive is recorded at GDH station in Greenland, where the 1907 Mw 7.2 earthquake in Tajikistan is recorded on smoked paper. (2) The first Danish earthquake is a local event close to Copenhagen in 1930. (3) We have illustrated the 50 megaton nuclear explosion in Novaya Zemlya in 1961—the largest nuclear test explosion ever. (4) The M 9.2 earthquake in Alaska in 1964 recorded on several instruments at COP. (5) A local earthquake in northeast Greenland recorded both on paper on World-Wide Standard Seismographic Network instruments and digitally on a modern broadband instrument.

Study of low-magnitude seismic events near the Novaya Zemlya nuclear test site

1997 ◽  
Vol 87 (6) ◽  
pp. 1563-1575
Author(s):  
Frode Ringdal
Keyword(s):  
Monitoring Network ◽  
Test Site ◽  
Nuclear Test ◽  
P Wave ◽  
Scaling Effects ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Novaya Zemlya ◽  
Source Scaling ◽  
Low Magnitude

Abstract A study of available seismic data shows that all but one of the 42 known underground nuclear explosions at Novaya Zemlya have been detected and located by stations in the global seismic network. During the past 30 years, only one seismic event in this area has been unambiguously classified as an earthquake (1 August 1986, mb = 4.3). Several other small events, most of which are thought to be either chemical explosions or aftereffects of nuclear explosions, have also been detected. Since 1990, a network of sensitive regional arrays has been installed in northern Europe in preparation for the global seismic monitoring network under a comprehensive nuclear test ban treaty (CTBT). This regional network has provided a detection capability for Novaya Zemlya that is shown to be close to mb = 2.5. Three low-magnitude events have been detected and located during this period, as discussed in this article: 31 December 1992 (mb = 2.7), 13 June 1995 (mb = 3.5), and 13 January 1996 (mb = 2.4). To classify the source types of these events has proved very difficult. Thus, even for the mb = 3.5 event in 1995, we have been unable to provide a confident classification of the source as either an earthquake or explosion using the available discriminants. A study of mb magnitude in different frequency bands shows, as expected, that the calculation of mb at regional distances needs to take into account source-scaling effects at high frequencies. Thus, when comparing a 4 to 8 or 8 to 16 Hz filter band to a “teleseismic” 2 to 4 Hz band, the smaller events have, relatively speaking, significantly more high-frequency energy (up to 0.5 mb units) than the larger events. This suggests that a P-wave spectral magnitude scale might be appropriate. The problem of accurately locating small events using a sparse array network is addressed using the 13 January 1996 event, which was detected by only two arrays, as an illustrative example. Our analysis demonstrates the importance of using accurately calibrated regional travel-time curves and, at the same time, illustrates how array processing can be used to identify an interfering phase from a local disturbance, thereby avoiding location errors due to erroneous phase readings.

Multiple inner core reflections from a Novaya Zemlya explosion

1972 ◽  
Vol 62 (4) ◽  
pp. 1063-1071 ◽  
Author(s):  
R. D. Adams
Keyword(s):  
Lower Bound ◽  
Inner Core ◽  
Nuclear Explosion ◽  
Outer Core ◽  
Low Velocity ◽  
Mantle Boundary ◽  
Core Mantle Boundary ◽  
Novaya Zemlya ◽  
The Core ◽  
Velocity Channel

Abstract The phases P2KP, P3KP, and P4KP are well recorded from the Novaya Zemlya nuclear explosion of October 14, 1970, with the branch AB at distances of up to 20° beyond the theoretical end point A. This extension is attributed to diffraction around the core-mantle boundary. A slowness dT/dΔ = 4.56±0.02 sec/deg is determined for the AB branch of P4KP, in excellent agreement with recent determinations of the slowness of diffracted P. This slowness implies a velocity of 13.29±0.06 km/sec at the base of the mantle, and confirms recent suggestions of a low-velocity channel above the core-mantle boundary. There is evidence that arrivals recorded before the AB branch of P2KP may lie on two branches, with different slownesses. The ratio of amplitudes of successive orders of multiple inner core reflections gives a lower bound of about 2200 for Q in the outer core.

scholarly journals Features of creating multi-time thematic animations of the Arctic environment pollution on the example of Novaya Zemlya

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Andrey Medvedev ◽  
Natalia Alekseenko ◽  
Maria Arsentyeva
Keyword(s):  
Time Scales ◽  
Radioactive Contamination ◽  
Arctic Region ◽  
Test Site ◽  
Nuclear Test ◽  
The Arctic ◽  
Novaya Zemlya Archipelago ◽  
Novaya Zemlya ◽  
The Creation ◽  
The Arctic Region

<p><strong>Abstract.</strong> The Arctic region is currently at the next stage of increased interest not only from the Arctic States, but also from the entire world community. The main pollutants in the region are oil and gas products, heavy metals, chemical and radioactive contamination. The Arctic region of the Russian Federation has experienced a strong anthropogenic impact of radionuclides due to the use of nuclear energy. The main source of pollution is nuclear testing. About 132 tests were conducted on Novaya Zemlya, including 87 atmospheric, 3 underwater and 42 underground tests. Another source of radioactive contamination is the operation of the naval and civil nuclear fleet, as well as nuclear power plants (on the Kola Peninsula and in Bilibino). Until 1963, most of the tests were carried out in the atmosphere and under water, but after the signing of the Moscow Treaty on August 5, 1963, which prohibits the testing of nuclear weapons in three environments (under water, in the atmosphere and outer space), all tests were carried out underground, in tunnels and wells.</p><p>The object of research and mapping is the territory of the Novaya Zemlya archipelago and the nuclear test site located on it. On the territory of the nuclear test site constantly there was an assessment of the radioecological situation. The scientific community is interested in the processes taking place on the New Earth. The territory of the archipelago is constantly involved in various Arctic programs aimed at monitoring the level of environmental pollution and reducing the number of sources of pollution.</p><p>The aim of this work is to create multi-time animations of nuclear tests and the results of radionuclide pollution. These animated cartographic images differ not only in their time scales, but also a large set of qualitative and quantitative characteristics that characterize the results of anthropogenic influence.</p><p>As sources for creation of cartographic animations were: field data, remote sensing data (RS), Open sources, marine navigation maps, DEM’s (AsterDem, ArcticDem, GEBCO), meteorological data, thematic maps (including atlases), topographic maps, literary sources. The main part of the information about Novaya Zemlya archipelago was taken from the works of the Arctic marine complex expedition, which are devoted to the nature, history, archeology and culture of the archipelago. To obtain complete information about the explosions and their energy release ranges, additional open sources were used, from which it is possible to learn about the type of explosion, its power and location (geographical coordinates).</p><p>Dynamic geo-imagery was developed and established by the following method: study of object mapping and the collection of primary spatial data – creation script dynamic geo-imagery – the creation of a geodatabase of research – the creation of the thematic maps and layout of geo-imagery in the graphic editor – create animations with different time scales.</p><p>During the creation of cartographic animations based on the collected data, a multi-time multi-scale cartographic animation was developed, which allowed using the original graphical solution to visualize three interconnected time scales, which allowed to visualize the processes of infiltration and propagation of radioactive inert gases.</p>

scholarly journals On site inspection for nuclear test ban verirication

1994 ◽  
Vol 37 (3) ◽  
Author(s):  
P. D. Marschall
Keyword(s):  
Nuclear Explosion ◽  
Nuclear Test ◽  
The Political ◽  
Chemical Weapon ◽  
Nuclear Explosions ◽  
Chemical Weapon Convention ◽  
On Site Inspection ◽  
Test Ban ◽  
Nuclear Test Ban ◽  
Test Ban Treaty

The problem of verifying compliance with a nuclear test ban treaty is mainly a technical one. However the problem of detecting, locating and identifying nuclear explosions has, since the late 1950s, been intimately involved with the political problems associated with negotiating a treaty. In fact there are few other areas in which policy, diplomacy and science have been so interwoven. This paper attempts to illustrate how technology can. be applied to solve some of the political problems which arise when considering the role of an On Site Inspection (OSI) to determine whether or not a nuclear explosion, in violation of a treaty, has occurred or not. It is hoped that the reader, with a scientific background, but with little or no experience of treaty negotiations, will gain an. insight as to how technical matters can interact with political requirements. The demands made on scientists to provide technical support for negotiating and rnonitoring compliance of a treaty have increased significanfly over the last 40 years. This is a period in which a number of major treaties have contained a significant technical component e.g. the Limited Test Ban Treaty (Threshold Treaty) and the Chemical Weapon Convention. This paper gives an indication of some of the political decisions which will have to be made and suggests some of the technical methods which are of value in the identification of a clandestine nuclear explosion.

scholarly journals Constraints on the location, depth and yield of the 2017 September 3 North Korean nuclear test from InSAR measurements and modelling

2019 ◽  
Vol 220 (1) ◽  
pp. 345-351 ◽  
Author(s):  
K M Sreejith ◽  
Ritesh Agrawal ◽  
A S Rajawat
Keyword(s):  
Large Scale ◽  
Surface Deformation ◽  
Nuclear Explosion ◽  
Source Parameters ◽  
Test Site ◽  
Nuclear Test ◽  
Interferometric Synthetic Aperture Radar ◽  
Surface Displacements ◽  
Detailed Surface ◽  
Scale Surface

SUMMARY The Democratic People's Republic of Korea (North Korea) conducted its sixth and largest affirmed underground nuclear test on 2017 September 3. Analysis of Interferometric Synthetic Aperture Radar (InSAR) data revealed detailed surface displacements associated with the nuclear explosion. The nuclear explosion produced large-scale surface deformation causing decorrelation of the InSAR data directly above the test site, Mt. Mantap, while the flanks of the Mountain experienced displacements up to 0.5 m along the Line-of-Sight of the Satellite. We determined source parameters of the explosion using the Bayesian inversion of the InSAR data. The explosive yield was estimated as 245–271 kiloton (kt) of TNT, while the previous yield estimations range from 70–400 kt. We determined the nuclear source at a depth of 542 ± 30 m below Mt. Mantap (129.0769°E, 41.0324°N). We demonstrated that the Bayesian modelling of the InSAR data reduces the uncertainties in the source parameters of the nuclear test, particularly the yield and source depth that are otherwise poorly resolved in seismic methods.

Quantitative assessment to the impact of InSAR ionospheric and tropospheric corrections on source parameter modelling: application to the 4th nuclear test, North Korea

2020 ◽  
Vol 224 (1) ◽  
pp. 86-99
Author(s):  
Meng Zhu ◽  
Qiming Zeng ◽  
Jian Jiao
Keyword(s):  
Standard Deviation ◽  
Focal Mechanism ◽  
Quantitative Assessment ◽  
Nuclear Explosion ◽  
Nuclear Test ◽  
Focal Mechanism Solution ◽  
Atmospheric Effects ◽  
Underground Nuclear Explosion ◽  
Tropospheric Corrections ◽  
The Impact

SUMMARY Although many studies have revealed that the atmospheric effects of electromagnetic wave propagation (including ionospheric and tropospheric water vapour) have serious impacts on Interferometric Synthetic Aperture Radar (InSAR) measurement results, atmospheric corrections have not been thoroughly and comprehensively investigated in many well-known cases of InSAR focal mechanism solutions, which means there is no consensus on whether atmospheric effects will affect the InSAR focal mechanism solution. Moreover, there is a lack of quantitative assessment on how much the atmospheric effect affects the InSAR focal mechanism solution. In this paper, we emphasized that it was particularly important to assess the impact of InSAR ionospheric and tropospheric corrections on the underground nuclear explosion modelling quantitatively. Therefore, we investigated the 4th North Korea (NKT-4) underground nuclear test using ALOS-2 liters-band SAR images. Because the process of the underground nuclear explosion was similar to the volcanic magma source activity, we modelled the ground displacement using the Mogi model. Both the ionospheric and tropospheric phase delays in the interferograms were investigated. Furthermore, we studied how the ionosphere and troposphere phase delays could bias the estimation of Mogi source parameters. The following conclusions were drawn from our case study: the ionospheric delay correction effectively mitigated the long-scale phase ramp in the full-frame interferogram, the standard deviation decreased from 1.83 to 0.85 cm compared to the uncorrected interferogram. The uncorrected estimations of yield and depth were 8.44 kt and 370.33 m, respectively. Compared to the uncorrected estimations, the ionospheric correction increased the estimation of yield and depth to 9.43 kt and 385.48 m, while the tropospheric correction slightly raised them to 8.78 kt and 377.24 m. There were no obvious differences in the location estimations among the four interferograms. When both corrections were applied, the overall standard deviation was 1.16 cm, which was even larger than the ionospheric corrected interferogram. We reported the source characteristics of NKT-4 based on the modelling results derived from the ionospheric corrected interferogram. The preferred estimation of NKT-4 was a Mogi source located at 129°04′22.35‘E, 41°17′54.57″N buried at 385.48 m depth. The cavity radius caused by the underground explosion was 22.66 m. We reported the yield estimation to be 9.43 kt. This study showed that for large-scale natural deformation sources such as volcanoes and earthquakes, atmospheric corrections would be more significant, but even if the atmospheric signal did not have much complexity, the corrections should not be ignored.

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