Earthquake data of the GEOSCOPE stations
      Download the SEED volume (20000 seconds of data)
Metadata and time series
List of miniSEED segments

 Theorical arrival times at GEOSCOPE stations
     Display arrival times at available GEOSCOPE stations

 Earthquake records

 Records from LHZ channel of GEOSCOPE stations

 Download graphic file in PDF format

This figure illustrates how the two blocks separated by the seismic fault are displaced during the earthquake. These movements are deduced from the SCARDEC focal mechanism, on the two possible fault planes. Additional information (tectonics, near-fault measurements) is required to determine which one of these two hypotheses corresponds to the real movements during the earthquake.

1) Overview

This page gathers information on earthquake characteristics (through the SCARDEC method, see below) and on GEOSCOPE data available for these events: The “data” tab provides access to the data seed file (20000s window starting at the earthquake origin time), provides access to the theoretical arrival times, shows earthquake waveforms for each station and channel, and presents the global Earth wave propagation through the visualization of the LHZ channel. The “mechanism” tab illustrates the geometry of the movement during the earthquake, along the two possible faults planes determined by SCARDEC analysis.

Several e-mail alerts are available, as soon as a new earthquake has been analyzed: (1) for all earthquakes, (2) for earthquakes with Mw>=6.5, and (3) for earthquakes with Mw>=7. Please contact Martin Vallée (vallee@ipgp.fr) to be added in one of these mailing lists.

2) Analysis of the earthquake source (SCARDEC method)

SCARDEC method uses the teleseismic body waves to retrieve the depth, focal mechanism, moment magnitude and source time function of earthquakes with magnitudes larger than 5.5-6. Details of the methodology are described in Vallée et al. [2011] and an application to all earthquakes with magnitude larger than 6 in the period 1992-2011 can be found in Vallée [2013]. The consolidated SCARDEC catalog, with full access to earthquake parameters and source time functions, can be found here.

In the near-real time configuration presented here, the solution is typically posted 45 minutes after earthquake occurrence. Solution includes a map summing up the SCARDEC results and a figure showing the agreement to the data. The map presents the earthquake location (together with the plate boundaries from Bird [2003] and the slab contours of SLAB 1.0 [Hayes et al., 2012]) and the main SCARDEC source parameters. Numerical values of focal mechanism parameters and seismic moment are written below the map. The data agreement figure compares the SCARDEC synthetics (red) with the FDSN data (black), in the frequency range used for focal mechanism determination. The name of GEOSCOPE stations is written in green.

the "detailed notes"

(1) Vallée, M., J. Charléty, A.M.G. Ferreira, B. Delouis, and J. Vergoz, SCARDEC : a new technique for the rapid determination of seismic moment magnitude, focal mechanism and source time functions for large earthquakes using body wave deconvolution, Geophys. J. Int., 184, 338-358, 2011.

(2) Vallée, M., Source time function properties indicate a strain drop independent of earthquake depth and magnitude, Nature Communications, doi: 10.1038/ncomms3606, 2013.