SMSPS Stephan Mueller Special Publication Series SMSPS Stephan Mueller Spec. Publ. Ser. 1868-4564 Copernicus Publications Göttingen, Germany 10.5194/smsps-4-261-2009 A seismic swarm near Neshkan, Chukotka, northeastern Russia, and implications for the boundary of the Bering plate Mackey K. G. 1 Fujita K. 1 Sedov B. M. 2 Gounbina L. V. 3 Kurtkin S. 3 Department of Geological Sciences, Michigan State University, East Lansing, MI 48824, USA Northeast Interdisciplinary Scientific Research Institute, Portovaya 16, Magadan 685000, Russia Magadan Affiliate, Geophysical Survey of Russia, Russian Academy of Sciences, Skuridina 6b, Magadan 685024, Russia 17 09 2009 4 261 271 Copyright: © 2009 K. G. Mackey et al. 2009 © European Geosciences Union 2009 This article is available from https://smsps.copernicus.org/articles/4/261/2009/smsps-4-261-2009.html The full text article is available as a PDF file from https://smsps.copernicus.org/articles/4/261/2009/smsps-4-261-2009.pdf

A seismic swarm lasting over two years occurred near the village of Neshkan, Chukotka, far northeastern Russia, beginning with a <i>M<sub>L</sub></i>, 4.2 (4.1 <i>m<sub>b</sub></i>) earthquake on 9 December 2002. The swarm generated considerable anxiety among the local populace and authorities. Two temporary seismic stations were deployed during the latter part of September 2003, and recorded over 150 events with magnitudes up to 3.0. Eighteen locatable events appear to form a northeast striking linear trend, parallel to other seismicity trends in Chukotka, extending 20 km to the southwest from the village. We interpret this trend as a previously unknown fault. A small pond located ~1 km west of the village drained and some apparent surface deformation was observed over the course of the earthquake sequence. Relocation of historic seismicity in the region shows that a magnitude 6.0 in 1996 may have ruptured an adjacent fault segment. Other, less well located but larger, teleseismic events earlier in the 20th century may also have occurred on or near this fault. The seismicity is consistent a proposed region of transtension along the northern boundary of a Bering plate.

 References Akinin, V. V. and Apt, Y. E.: Enmelen volcanoes (Chukchi Peninsula): Petrology of Alkaline Lavas and Deep-Seated Inclusions. SVKNII, Magadan, 1994 (in Russian). Aksenov, A. A., Dunaev, N. N., Ionin, A. S.., Kalinenko, V. V., Medvedev, V. S., Pavlidis, Y. A., and Yurkevich, M. G.: The Arctic shelf of Eurasia in Late Quaternary time. Nauka, Moscow, 1987 (in Russian). Anikeev, N. P., Vas'kov'skii, A. P., Drabkin, I. E., Popov, G. G., and Titov, V. A.: Tectonics, in: Northeast USSR, Geology of the USSR, 30, pt 2, edited by: Drabkin, I. E., Nedra, Moscow, 247–423, 1970 (in Russian). Belyi, V. F.: Okhotsk-Chukotka volcanogenic belt, Cenozoic volcanism, Magmatism, in: Northeast USSR, Geology of the USSR, 30, pt 2., edited by: Drabkin, I. E., Nedra, Moscow, 225–226, 1970 (in Russian). Bering Strait Field Party: Koolen metamorphic complex, NE Russia: Implications for the tectonic evolution of the Bering Strait region, Tectonics, 16, 713–729, 1997. Biswas, N. N., Aki, K., Pulpan, H., and Tytgat, G.: Characteristics of regional stresses in Alaska and neighboring areas, Geophys. Res. Lett., 13, 177–180, 1986. Chebrov, V. N. (Ed.): Olyutorka Earthquake of 20 (21) April 2006 in the Koryak Highlands – First Results of Investigations, Kamchatka Filial, Geophysical Survey, Russian Academy of Sciences, CD, 2007. Cheshko, A. L., Dubinina, E. O., Vakin, E. A., Lavrushin, V. Y., and Polyak, B. G.: The first data on hydrogen and oxygen isotopic compositions in the thermal mineral waters of eastern Chukotka, Dokl. Earth Sci., 395, 425–428, 2004. Cross, R. S. and Freymueller, J. T.: Evidence for and implications of a Bering plate based on geodetic measurements from the Aleutians and western Alaska, J. Geophys. Res., 113, B07405, https://doi.org/10.1029/2007JB005136, 2008. Dumitru, T. A., Miller, E. L., O'Sullivan, P. B., Amato, J. M., Hannula, K. A., Calvert, A. T., and Gans, P. B.: Cretaceous to Recent extension in the Bering Strait region, Alaska, Tectonics, 14, 549–563, 1995. Dziewonski, A. M., Ekström, G., and Maternovskaya, N. N.: Centroid-moment tensor solutions for October–December 1996, Phys. Earth Planet. In., 105, 95–108, 1998. Eittreim, S., Grantz, A., and Whitney, O. T.: Cenozoic sedimentation and tectonics of Hope Basin, southern Chukchi Sea, in: The Relationship of Plate Tectonics to Alaskan Geology and Resources, edited by: Sisson, A., Alaska Geological Society, Anchorage, B-1–B-11, 1979. Fujita, K. and Koz'min, B. M.: Seismicity of the Amerasian Arctic shelf and its relationship to tectonic features, in: 1992 Proceedings International Conference on Arctic Margins, edited by: Thurston, D. K. and Fujita, K., US Mineral Management Service, OCS Study MMS 94-0040, 307–312, 1994. Fujita, K., Mackey, K. G., McCaleb, R. C., Gunbina, L. V., Kovalev, V. N., Imaev, V. S., and Smirnov, V. N.: Seismicity of Chukotka, northeastern Russia, Geol. S. Am. S., 360, 259–272, 2002. Gorodinsky, M. E. (Ed.): Geologic Map of the Northeast USSR. Vsesoyuz Nauchnyi-Issledovatel'sky Geologichesky Institut, Leningrad, scale 1:5 000 000, 1982 (dated 1980). Grantz, A., May, S. D., and Hart, P. E.: Geology of the Arctic continental margin of Alaska, in: The Geology of Alaska, The Geology of North America, G-1, edited by: Plafker, G. and Berg, H. C., Geological Society of America, Boulder, 17–48, 1994. Grantz, A., Scholl, D. W., Toro, J., and Klemperer, S. L.: Geologic structure of Bering and Chukchi shelves adjacent to Bering-Chukchi deep transect and tectonostratigraphic terranes of adjacent landmasses, Geol. S. Am. S., 360, scale 1:3 000 000, 2002. Grinenko, O. V., Sergeenko, A. I., and Belolyubsky, I. N.: Paleogene and Neogene of Northeastern Russia, pt~1. Izd-vo YaNTs SO RAN, Yakutsk, 1998. Hudson, T. and Plafker, G.: Kigluaik and Bendeleben faults, Seward Peninsula, US Geological Survey Circular, 772-B, B47-B50, 1978. Kirschner, C. E.: Interior basins of Alaska, in: The Geology of Alaska, The Geology of North America, G-1, edited by: Plafker, G. and Berg, H. C., Geological Society of America, Boulder, 469–493, 1994. Lander, A. V., Bukchin, B. G., Kiryushin, A. V., and Droznin, D. V.: The tectonic environment and source parameters of the Khailino, Koryakia earthquake of March 8, 1991: Does a Beringia plate exist?, Computational Seismology and Geodynamics, 3, 80–96, 1996. Lazareva, A. P.: Earthquakes of the Arctic in 1970 and 1971, in: Earthquakes of the USSR in 1971, edited by: Gorbunova, I. V., Kondorskaya, N. V., and Shebalin, N. V., Nauka, Moscow, 145–149, 1975 (in Russian). Mackey, K. G., Fujita, K., Gunbina, L. V., Kovalev, V. N., Imaev, V. S., Koz'min, B. M., and Imaeva, L. P.: Seismicity of the Bering Strait region: Evidence for a Bering block, Geology, 25, 979–982, 1997. Mackey, K. G.: Seismological Studies in Northeast Russia, Ph.D. Dissertation, Michigan State University, 1999. Mackey, K. G., Fujita, K., Steck, L. K., and Hartse, H. E.: Seismic regionalization in eastern Russia, in: Proceedings of the 25$^th$ Seismic Research review – Nuclear Explosion Monitoring: Building the Knowledge Base, National Nuclear Security Administration, US Department of Energy, LA-UR-03-6029, 73–82, 2003. Moll-Stalcup, E. J.: Latest Cretaceous and Cenozoic magmatism in mainland Alaska, in: The Geology of Alaska, The Geology of North America, G-1, edited by: Plafker, G. and Berg, H. C., Geological Society of America, Boulder, 589–620, 1994. Natal'in, B. A.: Late Cretaceous – Tertiary deformations in the Chukotka Peninsula: Implications for the origin of the Hope Basin and the Herald thrust belt (Chukchi Sea), Geotectonics, 33, 489–504, 1999. Natal'in, B. A., Amato, J. M., Toro, J., and Wright, J. E.: Paleozoic rocks of northern Chukotka Peninsula, Russian Far East: Implications for the tectonics of the Arctic region, Tectonics, 18, 977–1003, 1999. Pol'kin, Y. I.: Chukchi Sea, in: Geologic Structure of the USSR and Regularities in the Distribution of Mineral Resources, 9, Seas of the Soviet Arctic, edited by: Gramberg, I. S. and Pogrebitsky, Y. E., Nedra, Leningrad, 67–79, 1984 (in Russian). Polyak, B. G., Lavrushin, V. Y., Cheshko, A. L., Vakin, E. A., and Dubinina, E. O.: Geothermal resources of the Chukchi Peninsula, Proc. World Geothermal Congress, Antalya, Turkey, paper 19–25, 2005. Shipilov, E. V.: On the graben-rift system of the Chukchi Sea, Izv. AN SSSR Geol., 1989(10), 96–107, 1989 (in Russian). Shipilov, E. V., Senin, B. V., and Yunov, A. Y.: Sedimentary cover and basement of the Chukchi Sea from seismic data, Geotectonics, 23, 456–463, 1989. Stein, R. S., King, G. C. P., and Lin, J.: Change in failure stress on the southern San Andreas fault system caused by the 1992 Magnitude=7.4 Landers earthquake, Science, 258, 1328–1332, 1992. Till, A. B., and Dumoulin, J. A.: Geology of Seward Peninsula and Saint Lawrence Island, in: The Geology of Alaska, The Geology of North America, G-1, edited by: Plafker, G. and Berg, H. C., Geological Society of America, Boulder, 141–152, 1994. Tolson, R. B.: Structure and stratigraphy of the Hope Basin, southern Chukchi Sea, Alaska, in: Geology and Resource Potential of the Continental Margin of Western North America and Adjacent Ocean Basins – Beaufort Sea to Baja California, edited by: Scholl, D. W., Grantz, A., and Vedder, J. G., Earth Science Series 6, Circum-Pacific Council for Energy and Mineral Resources, Houston, 59–71, 1987. Toro, J., Amato, J. M., and Natal'in, B.: Cretaceous deformation, Chegitun River area, Chukotka Peninsula, Russia: Implications for the tectonic evolution of the Bering Strait region, Tectonics, 22(3), 1021, https://doi.org/10.1029/2001TC001333, 2003. Turner, D. L. and Forbes, R. B. (Eds.): A Geological and Geophysical Study of the Geothermal Energy Potential of Pilgrim Springs, Alaska, Geophysical Institute, University of Alaska, UAG R-271, 1980.