ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Call number: STR 11/11
    In: Scientific technical report
    Pages: Online-Ressource
    Series Statement: Scientific technical report / Deutsches GeoForschungsZentrum GFZ 11/11
    Branch Library: GFZ Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2018-06-12
    Description: Abstract
    Description: The Halmahera island belongs to the North Moluccas province (Maluku Utara), Indonesia. This K-shaped island is located in the eastern part of the Moluccas Sea, the only active arc-arc collision complex on the Earth. The western arm of the K forms a volcanic arc due to the former subduction of the Moluccas Sea plate underneath Halmahera. The region is characterized by intense seismic activity at crustal, intermediate depth, and along the subducting plate. At crustal level the Halmahera seismicity along the two eastern arms of the K show strike-slip faulting style. In November 2015 a localized intense and energetic seismic activity started around Jailolo volcano in the West Halmahera Regency. The seismic sequence intermittently lasted until February 2016 and hundreds of events were felt by the population and several buildings were destroyed and damaged by the shaking. The largest shocks of the sequence have been located by global agencies (GEOFON and GCMT) showing normal faulting style. The temporal evolution of the seismicity seems to be more swarm-like type activity instead of mainshock-aftershock sequence. In spring 2016 a research project has been funded by the German's Humanitarian Aid program in collaboration with BMKG, Indonesia, with the goal of understanding the origin of the intense seismic activity and the related hazard. In summer 2016 we instrumented the area with a dense seismic network composed of 29 short period and 6 broad-band seismometers. The instruments deployment aims at characterizing the seismicity of the Jailolo region in relationship with the 2015-2016 seismic activity. The network will help to understand the seismo-tectonic of the area and the relation between seismicity and the volcanic activity at Jailolo volcano and possible link with the 2015-2016 swarm. Should the seismic activity intensify as in November 2015, we can record it and narrow down the underlying physical mechanisms. Waveform data are available from the GEOFON data centre, under network code 7G, and are embargoed until the end of 2021.
    Keywords: Broadband seismic waveforms ; Seismic monitoring ; Monitoring system ; Seismological stations
    Type: Other , Seismic Network
    Format: approx. 900GB
    Format: SEED data
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2011-09-26
    Description: Compared with seismic waves, near-field static deformation can provide more robust constraints on earthquake size and slip distribution because it is less sensitive to the rupture process and Earth structure. The static deformation data are now obtained using space-geodetic measurements. For early warning and rapid hazard assessment, such geodetic measurements are less useful because they are usually available only with a time delay of days to weeks or even longer. Recent studies have shown that coseismic static displacements can be estimated from modern seismometer records after an appropriate correction for baseline errors that may be caused by rotational motion, tilt, instrument, and other effects. For this purpose, several empirical baseline correction methods have been proposed. Algorithms, in which an acceleration or other acceleration record derived threshold is used to determine the timing of baseline shift, can be easily implemented. In practice, however, the baseline shift is not necessarily accompanying the strongest ground shaking; methods based on the threshold approach tend to lead to an over- or underestimation of the true baseline shift. Other correction schemes, which can be performed by manual calibration, rely on subjective decisions for the choice of correction parameters. In this paper, an automatic scheme is presented in which the method used to determine the baseline shift has a stronger physical basis. Case studies on the 1999 Chi-Chi, 2007 Tocopilla, 2008 Wenchuan, and 2010 Maule earthquakes, where the strong-motion data were obtained from different types of accelerometers, show that this automatic scheme is more robust than the previously suggested ones. In all test cases, the coseismic displacements recovered from the strong-motion records agree within 10%-20% with direct GPS measurements or indirect model predictions. In addition, the automatic scheme was also successfully used to correct the strong-motion records of a low-cost sensor obtained from a laboratory test.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2004-12-01
    Description: Aftershocks of the magnitude M (sub w) 6.4 Bingol earthquake of 1 May 2003 (eastern Turkey) were monitored by a local temporary seismic network. The spatial distribution of the aftershocks shows that the earthquake did not occur on the left-lateral East Anatolian fault, but perpendicular to it along a north-northwest-striking right-lateral fault. The event ruptured an area of 20 km by 8 km, but did not reach the Earth's surface. The aftershocks of the 2003 Bingol earthquake and those of the 1992 Erzincan earthquake seem to indicate the existence of a new seismically active right-lateral shear zone. Indeed, we show that historical earthquakes along both the North and East Anatolian fault led to positive changes in Coulomb failure stress for north-northwest-oriented right-lateral strike-slip faults in the Bingol epicentral area. Moreover, the existence of such faults is supported by remote-sensing data.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2011-03-17
    Description: A seismic antenna approach based on the generalized zero-lag cross-correlation method for rapid earthquake localization is proposed. This method is intended to be applied primarily for early warning, whenever the epicentre-to-target distances guarantee enough lead-time, rapid response purposes, and for those circumstances when a seismogenic area is not directly accessible with seismic stations or/and a network of instruments is concentrated within the area to be warned. The procedure we propose aims to provide useful information for magnitude determination and shake-maps generation. Indeed, it relies only on the first P-wave triggered arrivals from seismic stations, and is designed to work in real-time for the localization of events occurring outside of the network, that is, under conditions that might be detrimental to standard localization approaches. The procedure can by summarized by a few preliminary pre-seismic and real-time co-seismic steps. In the pre-seismic time-frame, for the cases where a large and dense network exists, waiting for all stations to trigger could dramatically reduce the available lead-time for the warning. Therefore, in such cases, the network could profitably be divided into sub-arrays, while also taking advantage of available earthquake recordings or simulated data sets. During the co-seismic time-frame, the main operations are: (1) individual on-site triggering by the P-wave of the seismic stations (e.g. by a STA/LTA algorithm); (2) real-time communication of key parameters (e.g. P-wave arrival time, and signal quality) to a main centre by SMS/WLAN; (3) setup of a pseudo data set, composed by a Gaussian function centred at the P-time, and with a bell width that can be set up proportional to the trigger signal-to-noise ratio (SNR); (4) calculation of a coherency map for the sub-array with triggered stations (preliminary sub-array location); and (5) stacking of coherency maps from the different sub-arrays (final location). By the stack of coherency maps estimated by the different sub-arrays in the last step of the procedure, the epicentral area’s location may be better constrained. This innovative approach for rapid localization was applied to both synthetic data, and real observations of two small earthquakes that occurred in the Marmara Sea, Turkey, which were recorded by the Istanbul Earthquake Rapid Response System. ©2011 Springer Science+Business Media B.V.
    Print ISSN: 1383-4649
    Electronic ISSN: 1573-157X
    Topics: Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2011-10-01
    Description: Compared with seismic waves, near-field static deformation can provide more robust constraints on earthquake size and slip distribution because it is less sensitive to the rupture process and Earth structure. The static deformation data are now obtained using space-geodetic measurements. For early warning and rapid hazard assessment, such geodetic measurements are less useful because they are usually available only with a time delay of days to weeks or even longer. Recent studies have shown that coseismic static displacements can be estimated from modern seismometer records after an appropriate correction for baseline errors that may be caused by rotational motion, tilt, instrument, and other effects. For this purpose, several empirical baseline correction methods have been proposed. Algorithms, in which an acceleration or other acceleration record derived threshold is used to determine the timing of baseline shift, can be easily implemented. In practice, however, the baseline shift is not necessarily accompanying the strongest ground shaking; methods based on the threshold approach tend to lead to an over- or underestimation of the true baseline shift. Other correction schemes, which can be performed by manual calibration, rely on subjective decisions for the choice of correction parameters. In this paper, an automatic scheme is presented, in which the method used to determine the baseline shift has a stronger physical basis. Case studies on the 1999 Chi-Chi, 2007 Tocopilla, 2008 Wenchuan, and 2010 Maule earthquakes, where the strong-motion data were obtained from different types of accelerometers, show that this automatic scheme is more robust than the previously suggested ones. In all test cases, the coseismic displacements recovered from the strong-motion records agree within 10%-20% with direct GPS measurements or indirect model predictions. In addition, the automatic scheme was also successfully used to correct the strong-motion records of a low-cost sensor obtained from a laboratory test.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...