The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

V. N. Koneshov - One of the best experts on this subject based on the ideXlab platform.

Eero Kataja - One of the best experts on this subject based on the ideXlab platform.

  • a short history of the sodankyla Geophysical Observatory
    1999
    Co-Authors: Eero Kataja
    Abstract:

    The first Geophysical Observatory at Sodankyla was the Polar Year Observatory in years 1882-84. The Finnish Academy of Science and Letters, established in 1908, set up the Sodankyla Geophysical Observatory in 1913 as a geomagnetic Observatory. Its activities increased before and during the Second Polar Year 1932-33, but then the Observatory was destroyed because of war in autumn 1944. The rebuilt Observatory started on January 1, 1946. During IGY (1957-58) the ionospheric station was started, as well as the seismological station. During the time 1961-71 there was an active period of construction. In 1973-92 an astronomical station (polar variation telescope) was run; this activity had been the original goal of the donation, which led to the establishing of the Observatory. After 1970 the activities of the Observatory have enhanced remarkably. In 1977 a receiving station of the EISCAT radar association was located at Sodankyla. A network of field stations is run, mainly in Northern Finland. In 1997 the Observatory joined to the University of Oulu. Sodankyla Geophysical Observatory (SGO) is situated near the southern edge of the Auroral Zone (Lat. 67°22’N, 26°38’E), 5 km south of the Sodankyla village on the left (eastern) bank of the Kitinen river. Northern Scandinavia is sometimes called a ‘natural Geophysical laboratory’ because of its unparalleled geographic, climatic and Geophysical location. For more than one hundred years, there has been remarkable scientific expedition activity both on the mainland and in the Arctic Ocean.

Hanna Silvennoinen - One of the best experts on this subject based on the ideXlab platform.

  • seismic observations at the sodankyla Geophysical Observatory history present and the future
    Geoscientific Instrumentation Methods and Data Systems, 2016
    Co-Authors: Elena Kozlovskaya, J Narkilahti, Jouni Nevalainen, Riitta Hurskainen, Hanna Silvennoinen
    Abstract:

    Abstract. Instrumental seismic observations in northern Finland started in the 1950s. They were originally initiated by the Institute of Seismology of the University of Helsinki (ISUH), but the staff of Sodankyla Geophysical Observatory (SGO) and later geophysicists of the University of Oulu (UO) were involved in the development of seismological observations and research in northern Finland from the very beginning. This close cooperation between seismologists and the technical staff of ISUH, UO, and SGO continued in many significant international projects and enabled a high level of seismological research in Finland. In our paper, we present history and current status of seismic observations and seismological research in northern Finland at the UO and SGO. These include both seismic observations at permanent seismic stations and temporary seismic experiments with portable seismic equipment. We describe the present seismic instrumentation and major research topics of the seismic group at SGO and discuss plans for future development of permanent seismological observations and portable seismic instrumentation at SGO as part of the European Plate Observing System (EPOS) research infrastructure. We also present the research topics of the recently organized Laboratory of Applied Seismology, and show examples of seismic observations performed by new seismic equipment located at this laboratory and selected results of time-lapse seismic body wave travel-time tomography using the data of microseismic monitoring in the Pyhasalmi Mine (northern Finland).

  • Seismic observations at the Sodankylä Geophysical Observatory: history, present and the futureitle of the manuscript
    2016
    Co-Authors: Elena Kozlovskaya, J Narkilahti, Jouni Nevalainen, Riitta Hurskainen, Hanna Silvennoinen
    Abstract:

    Abstract. Instrumental seismic observations in northern Finland started in 1950’s. They were originally initiated by the Institute of Seismology of the University of Helsinki (ISUH), but the staff of the Sodankylä Geophysical Observatory (SGO) and later, geophysicists of the University of Oulu (OU) were involved in development of seismological observations and research in northern Finland from the very beginning. This close cooperation between seismologists and technical staff of ISUH, OU and SGO continued later in a number of significant international projects and enabled a high level of seismological research in Finland. In our paper we present history and present state of seismic observations and seismological research in northern Finland at the OU and the SGO. This includes both seismic observations at permanent seismic stations and temporary seismic experiments by portable seismic equipment. We describe the present seismic instrumentation and major research topics of seismic group at the SGO and discuss the plans for future development of permanent seismological observations and portable seismic instrumentation at the SGO as a part of the EPOS-European Plate Observing System research infrastructure. We also present the research topics of recently organised Laboratory of Applied Seismology of the SGO, show examples of seismic observations performed by new seismic equipment of the Laboratory and selected results of time-lapse seismic body wave travel time tomography using the data of microseismic monitoring in the Pyhäsalmi Mine (northern Finland).

K. Hirata - One of the best experts on this subject based on the ideXlab platform.

  • Double seismic zone in the Hokkaido Island, Southern Kurile arc, derived from off-Kushiro permanent OBS and land-based observations
    2003 International Conference Physics and Control. Proceedings (Cat. No.03EX708), 2003
    Co-Authors: T. Watanabe, K. Hirata, H. Mikada, R. Otsuka, H. Takahashi, M. Kasahara, K. Suyehiro
    Abstract:

    We located hypocenters for more than two years, using combined datasets from land-based observations and ocean-bottom seismological data acquired by a permanent cable Geophysical Observatory system (JAMSTEC system), installed off Kushiro-Tokachi in July 1999. Hypocenter distribution characterizes that: 1) double seismic zone just east of the cabled Observatory system, 2) a relatively low seismicity west of the cabled system, and 3) characteristic shallow seismic activity below the cabled system.

  • Real-time Geophysical measurements on the deep seafloor using submarine cable in the southern Kurile subduction zone
    IEEE Journal of Oceanic Engineering, 2002
    Co-Authors: K. Hirata, M. Aoyagi, H. Mikada, K. Kawaguchi, Y. Kaiho, R. Iwase, S. Morita, I. Fujisawa, H. Sugioka, K. Mitsuzawa
    Abstract:

    A permanent real-time Geophysical Observatory using a submarine cable was developed and deployed to monitor seismicity, tsunamis, and other Geophysical phenomena in the southern Kurile subduction zone. The Geophysical Observatory comprises six bottom sensor units, two branching units, a main electro-optical cable with a length of 240 km and two land stations. The bottom sensor units are: 1) three ocean bottom broadband seismometers with hydrophone; 2) two pressure gauges (PGs); 3) a cable end station with environmental measurement sensors. Real-time data from all the undersea sensors are transmitted through the main electro-optical cable to the land station. The Geophysical Observatory was installed on the continental slope of the southern Kurile trench, southeast Hokkaido, Japan in July 1999. Examples of observed data are presented. Sensor noises and resolution are mentioned for the ocean bottom broadband seismometers and the PGs, respectively. An adaptable observation system including very broadband seismometers is scheduled to be connected to the branching unit in late 2001. The real-time Geophysical Observatory is expected to greatly advance the understanding of Geophysical phenomena in the southern Kurile subduction zone.

Y. Korsunskaya - One of the best experts on this subject based on the ideXlab platform.

  • Numerical Simulation of European VLF Network Response to X-Class Solar Flare in September 2017
    2018 2nd URSI Atlantic Radio Science Meeting (AT-RASC), 2018
    Co-Authors: Iliya Ryakhovskiy, A. Lyakhov, B. Gavrilov, Y. Poklad, S. Bekker, S. Kozlov, Y. Korsunskaya
    Abstract:

    We present the experimental evidence for European VLF network data on the response of the lower ionosphere and frequency-dependent VLF data under the consequent X-class solar flares 06 September and 10 September 2017. The stations under analysis include European AWESOM monitors, which are distributed over all Europe. Data from Geophysical Observatory “Mikhnevo” (MKH) of the Institute of Geosphere Dynamics (54.57N, 37.46E) covers frequency range from 1Hz to 100 kHz, thus allowing the monitoring of all VLF/LF transmitters as well as Schumann resonance. The monitoring is evaluated both in magnetic field channel by METRONIX MFS07 magnetometer (3 components) and in electric field channel by Rhode&Schwarz ESCI receiver (vertical electric field).