ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    facet.materialart.
    Unknown
    Coordinating OBS Parks in Europe (2012)
    In:  Geophysical Research Abstracts Vol. 14, EGU2012-9536, 2012
    Details
    Publication Date: 2020-02-12
    Description: Within Europe there are more than 380 Ocean Bottom Seismometers (OBS) distributed across 10 instrument parks in 6 countries. At least 120 of these OBS are wideband or broadband, over 260 can be deployed for at least 6 months at a time and 140 for at least one year. New parks are planned in two other European countries, which should add over 70 OBSs to this “fleet”. However, these parks are under the control of individual countries or universities and hence to date this has made it difficult to organize large-scale experiments, especially for seismologists without marine experience. There has recently been an initiative to coordinate the use of these distributed instruments and their data products, to encourage large-scale experiments, possibly with onshore and offshore components, by seismologists who have not necessarily used OBSs before. The ongoing or planned developments include: Helping scientists with marine-specific formalities such as ship requests; clearer explanations of the noise floors of OBS instrumentation; improved clarity of instrument pricing and availability; standardized data output formats and data validation; and archiving in established seismological data centers. These efforts should allow improved experiment design in scientifically interesting regions with an offshore component and an easier, clearer way to organize large-scale, multi-country experiments. We will present details of this initiative to help organize large-scale experiments, the particularities of OBS sensors and marine deployments, the available instrumentation and new developments.
    Keywords: 550 - Earth sciences
    Type: info:eu-repo/semantics/conferenceObject
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Coordinating OBS Parks in Europe (2012)
    In:  EPIC3EGU General Assembly, Vienna, Austria, 2012-04-22-2012-04-27
    Details
    Publication Date: 2019-07-17
    Description: Within Europe there are more than 380 Ocean Bottom Seismometers (OBS) distributed across 10 instrument parks in 6 countries. At least 120 of these OBS are wideband or broadband, over 260 can be deployed for at least 6 months at a time and 140 for at least one year. New parks are planned in two other European countries, which should add over 70 OBSs to this "fleet". However, these parks are under the control of individual countries or universities and hence to date this has made it difficult to organize large-scale experiments, especially for seismologists without marine experience. There has recently been an initiative to coordinate the use of these distributed instruments and their data products, to encourage large-scale experiments, possibly with onshore and offshore components, by seismologists who have not necessarily used OBSs before. The ongoing or planned developments include: Helping scientists with marine-specific formalities such as ship requests; clearer explanations of the noise floors of OBS instrumentation; improved clarity of instrument pricing and availability; standardized data output formats and data validation; and archiving in established seismological data centers. These efforts should allow improved experiment design in scientifically interesting regions with an offshore component and an easier, clearer way to organize large-scale, multi-country experiments. We will present details of this initiative to help organize large-scale experiments, the particularities of OBS sensors and marine deployments, the available instrumentation and new developments.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Conference , notRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Coordinating European OBS Parks (2013)
    In:  EPIC3IAHS-IAPSO-IASPEI Joint Assembly, Gothenburg, Sweden, 2013-07-22-2013-07-26
    Details
    Publication Date: 2019-07-17
    Description: Within Europe, more than 380 Ocean Bottom Seismometers (OBS) are distributed across 10 instrument parks in 6 countries. At least 120 of these OBS are wideband or broadband, over 260 can be deployed for at least 6 months at a time and 140 for at least one year. New parks are planned in two other European countries, which should add over 70 OBSs to this "fleet". However, these parks are under the control of individual countries or universities and hence to date this has made it difficult to organize large-scale experiments, especially for seismologists without marine experience. We report on a recent initiative to coordinate the use of these distributed instruments and their data products, to encourage large-scale experiments, possibly with onshore and offshore components, by seismologists who have not necessarily used OBSs before. The ongoing or planned developments include: Helping scientists with marine-specific formalities such as ship requests; clearer explanations of the noise floors of OBS instrumenta- tion; improved clarity of instrument pricing and availability; standardized data output formats and data validation; and archiving in established seismological data centers. These efforts should allow improved experiment design in scientifically interesting regions with an offshore component and an easier, clearer way to organize large-scale, multi-country experiments. We will present details of this initiative to help organize large-scale experiments, the particularities of OBS sensors and marine deployments, the available instrumentation and new developments.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Conference , notRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    Electronic Resource
    Electronic Resource
    Infrared Spectra of Transition Metal Alkoxides. (1964)
    s.l. : American Chemical Society
    Analytical chemistry 36 (1964), S. 2332-2337 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac60218a034
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    facet.materialart.
    Unknown
    An Automatic Kurtosis-Based P- and S-Phase Picker Designed for Local Seismic Networks (2014)
    Seismological Society of America (SSA)
    Details
    Publication Date: 2014-02-04
    Description: We present an automatic P - and S -wave onset-picking algorithm, using kurtosis-derived characteristic functions (CF) and eigenvalue decompositions on three-component seismic data. We modified the kurtosis CF ( Saragiotis et al. , 2002 ) to improve pick precision by computing the CF over several frequency bandwidths, window sizes, and smoothing parameters. Once phases are picked, our algorithm determines the onset type ( P or S ) using polarization parameters, removes bad picks using a clustering procedure and the signal-to-noise ratio (SNR) and assigns a pick quality index based on the SNR. We tested our algorithm on data from two different networks: (1) a 30-station, 100 x 100 km array of mostly onland wideband seismometers in a subduction context and (2) a four-station, 7 x 4 km array of ocean-bottom seismometers over a midocean ridge volcano. We compared picks from the automatic algorithm with manual and short-term average/long-term average (STA/LTA)-based automatic picks on subsets of each dataset. For the larger array, the automatic algorithm resulted in more locations than manual picking (133 versus 93 locations out of 163 total events detected), picking as many P onsets and twice as many S onsets as with manual picking or the STA/LTA algorithm. The difference between manual and automatic pick times for P -wave onsets was 0.01±0.08 s overall, compared with –0.18±0.19 s using the STA/LTA picker. For S -wave onsets, the difference was –0.09±0.23 s, which is comparable to the STA/LTA picker, but our picker provided nearly twice as many picks. The pick accuracy was constant over the range of event magnitudes (0.7–3.7 M l ). For the smaller array, the time difference between our algorithm and manual picks is 0.04±0.17 s for P waves and 0.07±0.08 s for S waves. Misfit between the automatic and manual picks is significantly lower using our procedure than using the STA/LTA algorithm.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
    Published by Seismological Society of America (SSA)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu) [Environmental Sciences] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-08-10
    Description: Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002–2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world’s first climate change “refugees.” We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 + /-20 mm. But GPS data reveal that the islands subsided by 117 + /-30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just before and after this period caused several hundreds of mm of sudden vertical motion, generating larger apparent sea-level changes than those observed during the entire intervening period. Our results show that vertical ground motions must be accounted for when evaluating sea-level change hazards in active tectonic regions. These data are needed to help communities and governments understand environmental changes and make the best decisions for their future.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Nature of upper crust beneath the Lucky Strike volcano using elastic full waveform inversion of streamer data (2014)
    Oxford University Press
    Details
    Publication Date: 2014-02-13
    Description: Seismic full waveform is an emerging technique for determining the fine-scale velocity structure of the subsurface. Here, we present results of elastic full waveform inversion (FWI) along three multichannel seismic lines at the Lucky Strike volcano on the Mid-Atlantic ridge that provides a velocity image of the upper oceanic crust with unprecedented resolution (50–100 m). We have used a two-step process combining downward continuation with a time-domain, elastic FWI. The downward continuation procedure enhances the refracted arrivals and wide-angle reflections, and reduces the scattering noise due to rough seafloor. Since both sources and receivers are downward continued to the seafloor, the computational cost of FWI is reduced, as one does not need to model the thick water layer. Our results clearly demarcate two layers within seismic Layer 2A; a low-velocity, highly heterogeneous layer likely reflecting the complexity of accretion that is underlain by a more homogeneous high-velocity gradient layer. The base of Layer 2A is defined as a lithological boundary that can be offset by faulting. Thick (〉400 m) units of anomalously low-velocity material (〈2.5 km s –1 ) beneath different summital edifices on the central volcano indicate that a thick pile of high-porosity extrusive rocks can be supported without collapsing, suggesting that while in general there is pore closure with depth this is not the cause of high velocities we observe. Hydrothermal deposition sealing of small-scale porosity is shown to be a secondary process, which likely explains the upper crustal velocity increase with age, but is not responsible for the high-velocity gradient Layer 2A. Finally, the rapid thinning of the entire Layer 2A in the vicinity of the main normal faults suggests the tectonic thinning of a geologically defined layer, further confirming the lithological origin of the high-velocity gradient zone at the base of seismic Layer 2A.
    Print ISSN: 0956-540X
    Electronic ISSN: 1365-246X
    Topics: Geosciences
    Published by Oxford University Press on behalf of The Deutsche Geophysikalische Gesellschaft (DGG) and the Royal Astronomical Society (RAS).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Modeling Parasite Dynamics on Farmed Salmon for Precautionary Conservation Management of Wild Salmon (2013)
    Public Library of Science
    Details
    Publication Date: 2013-04-05
    Electronic ISSN: 1932-6203
    Topics: Medicine , Natural Sciences in General
    Published by Public Library of Science
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Strong seismic heterogeneity in layer 2A near hydrothermal vents at the Mid-Atlantic Ridge (2011)
    American Geophysical Union
    Details
    Publication Date: 2011-07-01
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by American Geophysical Union
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Shallow-Water Broadband OBS Seismology (2010)
    Seismological Society of America
    Details
    Publication Date: 2010-07-27
    Description: The recent development of broadband ocean-bottom seismometers that can be deployed for more than a year has led to the construction of large ocean-bottom seismometer (OBS) fleets and to many successful experiments studying Earth structure and tectonics beneath the oceans. However, ocean surface waves raise noise levels at deep ocean-floor sites far above those at continental sites in the microseism band between 0.2 and 10 sec period, and currents and ocean waves raise noise levels at longer periods. Broadband OBSs are rarely deployed in shallow water because of a fear of loss due to bottom trawling and an expectation of very high noise levels from strong currents and the nearby ocean surface. However, these noise sources can be overcome such that shallow OBS deployments may provide noise levels that are comparable to deep-water sites at periods 〉10 sec and lower than deep-water sites at shorter periods. Burial of the instrument into the sediments can shield the seismometer from current noise, while the noise from deformation under wave loading can be removed using pressure gauge data. We predict the noise levels can be reduced to allow the detection of Rayleigh waves from 20 to 200 sec period with good signal-to-noise ratio (SNR) from teleseismic earthquakes as small as M (sub w) 5. Short-period (〈2 sec) noise levels will be 20-30 dB lower in shallow water than in deep water because short-period microseisms are greatly attenuated during propagation from deep to shallow water. Short-period (0.5-2 sec) teleseismic body waves should be detected with good SNR from events as small as M (sub w) 4.5.
    Print ISSN: 0037-1106
    Electronic ISSN: 1943-3573
    Topics: Geosciences , Physics
    Published by Seismological Society of America
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...