Seismometers at the End of the World

23 Jul

Seismic sensors built by Gaiacode have just been installed in Tierra del Fuego at the southermost tip of the South American continent. It is an augmentation of an existing network and strengthens the monitoring efforts of the seismicity of the area. The data are transmitted in real time to the central monitoring facility in the Argentinian port city of Ushuaia.

While seismicity in South America is mainly associated with the subducting Nazca-Plate along the whole west coast of the continent, several destructive earthquakes have occured in the recent past along the very southern tip of the continent. The last of these temblors happened in 1949 and had magnitudes of 7.5 and 7.8 respectively. These quakes occured along the active Magallanes-Fagnano Fault System - a continental transform fault - which strikes through the southermost parts of Chile and Argentina, posing a substantial seismic hazard to cities like Ushuaia (Argentina) and Punta Arenas (Chile).

The Rio Grande Astronomical Station, operated by the Argentinian National University of La Plata, has been carrying out its seismology program in Tierra del Fuego since 1992. To monitor the seismicity of the region, it currently operates a network of several seismic stations. This network was recently augmented by Gaiacode's "Digital THETA" seismometers.  

Digital Theta

The Digital THETA is a mid-range broaband seismometer with an upper corner frequency of 120 seconds. It is fitted with a TAU digitizer to allow digitial data output and real time transmission to the central seismic observatory site in Ushuaia.

One of the first earthquakes the Digital THETA recorded in Tierra del Fuego was a M=6.7 earthquake of an intermediate depth of a 190 km under the Argentinian Andes at an epicentral distance of almost 1900 km. Using Gaiacodes OMEGA software, the time series of the three seismometer components is shown on the right, the corresponding spectra on the left.

M 6.7 Agentinian EQ

For more information about this project, contact Ampere, our partner and distributor for Latin America, or Gaiacode's main office in the United Kingdom.

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