scholarly journals Identifying and Correcting Timing Errors at Seismic Stations in and around Iran

2017 ◽  
Vol 88 (6) ◽  
pp. 1472-1479 ◽  
Author(s):  
Ellen M. Syracuse ◽  
W. Scott Phillips ◽  
Monica Maceira ◽  
Michael L. Begnaud
Keyword(s):  
Seismic Stations ◽  
Timing Errors

An Evaluation of the Timing Accuracy of Global and Regional Seismic Stations and Networks

2021 ◽  
Author(s):  
Yi Yang ◽  
Xiaodong Song ◽  
Adam T. Ringler
Keyword(s):  
Inner Core ◽  
Seismic Station ◽  
Temporal Changes ◽  
Time Range ◽  
Timing Accuracy ◽  
Seismic Stations ◽  
Arrival Times ◽  
Timing Errors ◽  
Repeating Earthquakes ◽  
Core Boundary

Abstract Clock accuracy is a basic parameter of any seismic station and has become increasingly important for seismology as the community seeks to refine structures and dynamic processes of the Earth. In this study, we measure the arrival time differences of moderate repeating earthquakes with magnitude 5.0–5.9 in the time range of 1991–2017 at the same seismic stations by cross-correlating their highly similar waveforms and thereby identify potential timing errors from the outliers of the measurements. The method has very high precision of about 10 ms and shows great potential to be used for routine inspection of the timing accuracy of historical and future digital seismic data. Here, we report 5131 probable cases of timing errors from 451 global and regional stations available from the Incorporated Research Institutions for Seismology Data Management Center, ranging from several tens of milliseconds to over 10 s. Clock accuracy seems to be a prevailing problem in permanent stations with long-running histories. Although most of the timing errors have already been tagged with low timing quality, there are quite a few exceptions, which call for greater attention from network operators and the seismological community. In addition, seismic studies, especially those on temporal changes of the Earth’s media from absolute arrival times, should be careful to avoid misinterpreting timing errors as temporal changes, which is indeed a problem in some previous studies of the Earth’s inner core boundary.

Seismic-monitoring changes and the remote deployment of seismic stations (seismic spider) at Mount St. Helens, 2004-2005

2008 ◽  
pp. 129-140 ◽  
Author(s):  
Patrick J. McChesney ◽  
Marvin R. Couchman ◽  
Seth C. Moran ◽  
Andrew B. Lockhart ◽  
Kelly J. Swinford ◽  
...  
Keyword(s):  
Seismic Monitoring ◽  
Seismic Stations ◽  
Mount St Helens

scholarly journals Earthquake location in tectonic structures of the Alpine Chain: the case of the Constance Lake (Central Europe) seismic sequence

2021 ◽  
Author(s):  
Francesca D’Ajello Caracciolo ◽  
Rodolfo Console
Keyword(s):  
Central Europe ◽  
Velocity Model ◽  
Moho Depth ◽  
Seismic Sequence ◽  
Tectonic Structures ◽  
Study Region ◽  
Waveform Data ◽  
Seismic Stations ◽  
Velocity Models ◽  
Master Event

AbstractA set of four magnitude Ml ≥ 3.0 earthquakes including the magnitude Ml = 3.7 mainshock of the seismic sequence hitting the Lake Constance, Southern Germany, area in July–August 2019 was studied by means of bulletin and waveform data collected from 86 seismic stations of the Central Europe-Alpine region. The first single-event locations obtained using a uniform 1-D velocity model, and both fixed and free depths, showed residuals of the order of up ± 2.0 s, systematically affecting stations located in different areas of the study region. Namely, German stations to the northeast of the epicenters and French stations to the west exhibit negative residuals, while Italian stations located to the southeast are characterized by similarly large positive residuals. As a consequence, the epicentral coordinates were affected by a significant bias of the order of 4–5 km to the NNE. The locations were repeated applying a method that uses different velocity models for three groups of stations situated in different geological environments, obtaining more accurate locations. Moreover, the application of two methods of relative locations and joint hypocentral determination, without improving the absolute location of the master event, has shown that the sources of the four considered events are separated by distances of the order of one km both in horizontal coordinates and in depths. A particular attention has been paid to the geographical positions of the seismic stations used in the locations and their relationship with the known crustal features, such as the Moho depth and velocity anomalies in the studied region. Significant correlations between the observed travel time residuals and the crustal structure were obtained.

Block codes capable of correcting both additive and timing errors

1980 ◽  
Vol 26 (4) ◽  
pp. 393-400 ◽  
Author(s):  
I. Iizuka ◽  
M. Kasahara ◽  
T. Namekawa
Keyword(s):  
Block Codes ◽  
Timing Errors

scholarly journals Twin enigmatic microseismic sources in the Gulf of Guinea observed on intercontinental seismic stations

2013 ◽  
Vol 194 (1) ◽  
pp. 362-366 ◽  
Author(s):  
Yingjie Xia ◽  
Sidao Ni ◽  
Xiangfang Zeng
Keyword(s):  
North America ◽  
Temporal Variation ◽  
Crustal Structure ◽  
Source Region ◽  
Broad Band ◽  
Active Volcano ◽  
Gulf Of Guinea ◽  
Waveform Data ◽  
Seismic Stations ◽  
The Earth

Abstract Based on studies of continuous waveform data recorded on broad-band seismograph stations in Africa, Europe and North America, we report evidences for two temporally persistent and spatially localized monochromatic vibrating sources (around 0.036 and 0.038 Hz, respectively) in the Gulf of Guinea, instead of just one source (0.038 Hz or 26 s) found 50 yr ago. The location of the 0.036 Hz source is close to the Sao Tome Volcano, therefore it may be related to volcano processes. However, the 0.038 Hz source cannot be explained with known mechanisms, such as tectonic or oceanic processes. The most likely mechanism is volcano processes, but there is no reported active volcano in source region. Such repetitive vibration sources may provide valuable tools for detecting temporal variation of crustal structure of the Earth.

Sign in / Sign up

Export Citation Format

Share Document