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57 documents found in 201ms
# 1
Haberland, Christian • Seneviratne, Mahinda • Dreiling, Jennifer
Abstract: A temporary seismic network was installed in Sri Lanka for a time period of 13 months. The stations were equipped with Earth Data EDR-210 digital recorders and Trillium 120 PA, Güralp C3E and Güralp CMG-3ESP broadband sensors. Main aim of the network is to shed light on the crustal and upper mantle structure beneath the island. Also local seismic activity is studied.
# 2
Haberland, C. • Rietbrock, A. • Asch, G. • Chong, G.
Abstract: Local seismic network in Northern Chile, Southern Bolivia. (Grant-number: GIPP199604) Waveform data is available from the GEOFON data centre. License: “Creative Commons Attribution-ShareAlike 4.0 International License” (CC BY-SA).
# 3
Dias, N.A. • Silveira, G. • Haberland, C.
Abstract: The lithosphere of Iberia has been formed through a number of processes of continental collision and extension. In Lower Paleozoic, the collision of three tectonics blocks produced the Variscan Orogeny, the main event of formation of the Iberian lithosphere. The subsequent Mesozoic rifting and breakup of the Pangea had a profound effect on the continental crust of the western border of Iberia. Since the Miocene, the southern interaction between Africa and Iberia is characterized by a diffuse convergent margin that originates a vast area of deformation. The impact of this complex tectonic in the structure of the Iberian Lithosphere remains an incognito, especially in its western part beneath Portugal. While the surface geology is considerably studied and documented, the crustal and lithospheric structures are not well constrained. The existing knowledge relating the observed surface geology and Lithospheric deep structures is sparse and sometimes incoherent. The seismic activity observed along West Iberia is intensely clustered on few areas, namely on north Alentejo, Estremadura and Regua-Verin fault systems. Some of the problems to address are: What is the relation between surface topography and the deep crustal/lithospheric structure? How was it influenced by the past tectonic events? Which was the deep driving factor behind the tectonic units observed at surface: Lithosphere-Astenosphere boundary structure or deeper mantle structure? How the upper mantle and the Lithosphere-Astenosphere transition zone accommodated the past subduction? Which is its role and influence of the several tectonic units, and their contacts, in the present tectonic regime and in the stress field observed today? Is the anomalous seismicity and associated crustal deformation rates, due to an inherited structure from past orogenies? The main goal of this work is a 3D detailed image of the “slice” of the Earth beneath Western Iberia, by complementing the permanent seismic networks operating in Portugal and Spain. The different scales involved require the usage of several passive seismological methods: Local-Earthquake Tomography for fine structure of seismogenic areas, ambient noise tomography for regional crustal structure, Receiver Functions for Lithospheric structure and Surface-wave tomography for large scale Listosphere-Astenosphere structure. Crustal and Mantle seismic anisotropy analysis, coupled with source analysis and correlation with current geodetic measurements will allow establishing a reference 3D anisotropy model of present and past processes.
# 4
Heit, B. • Weber, M. • Tilmann, F. • Haberland, C. • Jia, Y. • (et. al.)
Abstract: The SWATH-D experiment is dense deployment of 154 seismic stations in the Central and Eastern Alps between Italy and Austria, complementing the larger-scale sparser AlpArray Seismic Network (AASN). SWATH-D will provide high resolution images from the surface into the upper mantle, and allow observations of local seismicity. SWATH-D focuses on a key area of the Alps where the hypothesized flip in subduction polarity has been suggested, and where an earlier seismic profile (TRANSALP) has imaged a jump in the Moho. Where mains power is available (at ca. 80 sites) stations are providing realtime data via the cellphone network and are equipped with Güralp CMG-3EPSC (60s) seismometers and Earth Data Recorders EDR-210. The rest of the stations are offline and consist mainly of Nanometrics Trillium Compact (120s) and Güralp CMG-3EPSC (60s) seismometers equipped with either Omnirecs CUBE3 or PR6-24 Earth Data Loggers. All stations are equipped with external GPS antennas and the sampling rate is 100 Hz (Heit, et al., 2018). The network will operate for 2 years starting in July 2017. The Swath-D data will be used directly by 20 individual proposals of the MB-4D Priority Program (Mountain Building Processes in Four Dimensions, 2017) of the German Research Foundation (DFG) and data products derived from it will contribute to additional 13 proposals. SWATH-D is thus an important link between the MB-4D Priority Program and the international AlpArray communities and a scientific service to many of the proposals within the DFG Priority Program. Waveform data are available from the GEOFON data centre, under network code ZS, and are embargoed until August 2023. After the end of embargo, data will be openly available under CC-BY 4.0 license according to GIPP-rules.
# 5
Schurr, B. • Yuan, X. • Kufner, S. • Bloch, W.
Abstract: The Sarez Pamir aftershock seismic network was installed two months after the 7 December 2015, Mw7.2 Sarez Pamir earthquake in the eastern Pamir highland of Tajikistan. In the first recording period until September 2016, the stations were distributed along the Sarez-Karakul fault system. In September 2016 part of the stations were moved into the southern Pamir. In total the network consisted of eight stations on 13 sites, equipped with broad band, 3-component seismometers of type Trillium Compact. The data were recorded using Earth Data recorders (EDR), recording was continuous at a sample rate of 100Hz.The principal aim of the network was to record the aftershock sequence of the Sarez earthquake and to augment the coeval East Pamir China seismic network and the earlier TIPAGE and TIPTIMON seismic networks. Waveform data are available from the GEOFON data centre, under network code 9H, and are embargoed until January 2021.
# 6
Yuan, X. • Schurr, B. • Bloch, W. • Xu, Q. • Zhao, J.
Abstract: The East Pamir seismic network was located on the eastern flank of the Pamir highlands and the in the foreland of the adjacent Tarim Basin of western China. It was in operation between August 2015 and May 2017 and consisted of 30 broad band, 3-component seismometers of type Güralp CMG-3ESP or Nanometrics Trillium 120. The data were recorded using Earth Data PS6-24 "EDL" recorders, continuously at a sample rate of 100Hz, with an average station distance of ~20km. The network was designed to augment the earlier TIPAGE and TIPTIMON seismic networks.The principal aim of the network was to characterize the current deformation field in the region. It further recorded the 2015 M7.2 Sarez earthquake. Waveform data are available from the GEOFON data centre, under network code 8H, and are embargoed until January 2021.
# 7
Sens-Schönfelder, C. • Delatre, M.
Abstract: Ketzin in a small town 20km west of Berlin that hosts a research facility for underground storage. Starting in 2008 the site was used to investigate the onshore geological storage of carbon dioxide (Liebscher et al., 2013). Among a large variety of downhole monitoring measurements and repeated 3D seismics above the storage formation, a seismic network was installed to investigate the possibility of monitoring subsurface processes related to the injection of CO2 with passive seismic recordings (Gassenmeier et al., 2015). The network was operated for 12 month from early 2011 to 2012 and consisted of 10 Guralp broadband sensors of the Geophysical Instrument Pool Potsdam (GIPP). Five instruments were located at the drilling site and five instruments were installed at a distance up to 3.5km around the injection site. The Instruments were either installed in basements or buried at a depth of about 70cm (KTE, KTF and KTG). The installation was supported by the German Federal Ministry of Education and Research (BMBF, grant 03G0736A) by the University of Leipzig and the GIPP.
# 8
Shapiro, N. M. • Sens-Schönfelder, C. • Lühr, B. G. • Weber, M. • Abkadyrov, I. • (et. al.)
Abstract: The KISS network was installed in the frame of the "Klyuchevskoy Investigation - Seismic Structure of an extraordinary volcanic system" project and recorded data between summer 2015 and summer 2016 in one of the world's largest clusters of subduction volcanoes - the Klyuchevskoy volcanic group (KVG). It is located in eastern Russia at the northern end of the Kuril-Kamchatka subduction zone close to its intersection with the Aleutian arc and the north-western termination of Hawaii-Emperor seamount chain. Additional to the 4700m high Mount Klyuchevskoy the KVG contains 12 other volcanoes that have together erupted about 1 cubic meter rock per second averaged over the past 10,000 years. Among those Klyuchevskoy, Bezymianny and Tolbachik were the most active ones during the last decades with eruptions styles ranging from explosive to Hawaiian-type. The KISS experiment is designed to investigate the volcanic and seismic processes and its structural setting in the KVG. The network covers a circular region of about 80km diameter with some linear extensions. It includes data from 77 temporary seismic stations with broadband and short period sensors that were installed on concrete plates in about 60cm deep holes. Due to the local conditions the stations were battery powered and could not be serviced during the experiment. GPS reception of the digitizers was not continuous at all stations due to thick snow cover and vegetation.
# 9
Institute of Seismology, University of Helsinki
Abstract: The Institute of Seismology, University of Helsinki (ISUH) was founded in 1961 as a response to the growing public concern for environmental hazards caused by nuclear weapon testing. Since then ISUH has been responsible for seismic monitoring in Finland. The current mandate covers government regulator duties in seismic hazard mitigation and nuclear test ban treaty verification, observatory activities and operation of the Finnish National Seismic Network (FNSN) as well as research and teaching of seismology at the University of Helsinki.The first seismograph station of Finland was installed at the premises of the Department of Physics, University of Helsinki in 1924. However, the mechanical Mainka seismographs had low magnification and thus the recordings were of little practical value for the study of local seismicity. The first short-period seismographs were set up between 1956 and 1963. The next significant upgrade of FNSN occurred during the late 1970’s when digital tripartite arrays in southern and central Finland became fully operational, allowing for systematic use of instrumental detection, location and magnitude determination methods. By the end of the 1990’s, the entire network was operating using digital telemetric or dial-up methods. The FNSN has expanded significantly during the 21st Century. It comprises now 36 permanent stations. Most of the stations have Streckeisen STS-2, Nanometrics Trillium (Compact/P/PA/QA) or Guralp CMG-3T broad band sensors. Some Teledyne-Geotech S13/GS13 short period sensors are also in use. Data acquisition systems are a combination of Earth Data PS6-24 digitizers and PC with Seiscomp/Seedlink software or Nanometrics Centaurs. The stations are connected to the ISUH with Seedlink via Internet and provide continuous waveform data at 40 Hz (array) or 100-250 Hz sampling frequency. Further information about instrumentation can be found at the Institute’s web site (www.seismo.helsinki.fi). Waveform data are available from the GEOFON data centre, under network code HE, and arefully open.
# 10
Cesca, Simone • López Comino, José Ángel • Kühn, Daniela • Dahm, Torsten
Abstract: A temporary installation has been realized in the Netherlands, in the region of the Groningen gas field. The objective of this installation is to test the usage of a conventional array layout for detection of microseismicity. The region of the Groningen gas field is an excellent test ground, since the operating company NAM (Nederlandse Aardolie Maatschappij) installed a multitude of shallow borehole stations from 2014 to 2017, of which 65 – in addition to the already existing shallow borehole stations installed by KNMI (Koninklijk Nederlands Meteorologisch Instituut) – were already online during the time of measurement, thus ensuring an earthquake catalogue that is complete down to low magnitudes during the time of array installation. The site for the installation was decided together with local parties involved in the seismicity monitoring, i.e. KNMI and NAM, and was located close to the village of Wittewierum. Stations were installed from the 12th of July 2016 to the 29th of August 2016 (49 days). The array was composed of 9 stations. The array was constructed in three concentric rings of 75 m, 150 m and 225 m diameter including a central station, but the geometry had to be adapted to the local conditions. Each station consisted of a broadband sensor (Trillium 120 s), an acquisition system (CUBE datalogger), a battery, and a GPS antenna. The entire system was installed at ~1 m depth (apart from GPS and transmission antennas), requiring only the digging of shallow holes, one for the installation of a thin concrete plate and the sensor, another one for a box containing the remaining instrumentation. The array stations recorded continuously with little outages; only station WAR1 stopped recording on the 22nd of August and station WAR7 stopped recording from 20th to 22nd of August. Waveform data is available from the GEOFON data centre, under network code 1C, and is fully open.
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