The Central and Eastern United States Network and Repeating Earthquakes in ENA

English Abstract:

The recent deployment of Transportable Array (TA) seismographic stations of the USArray project by the Incorporated Research Institutions for Seismology (IRIS) in the eastern United States has greatly improved the earthquake monitoring and research in the region. Over 160 TA stations in the eastern United States were selected to be retained beyond their nominal deployment period of about two years. These selected TA stations will be gradually upgraded from 40 to 100 samples/second by the fall of 2015 and will form the Central and Eastern United States Network (CEUSN) with network code “N4”. CEUSN will be operated by IRIS until the end of 2017. The CEUSN and existing permanent seismographic stations of the national and regional networks in the region such as, Canadian National Seismic Network (CN), US National Seismic Network (US), Lamont Cooperative Seismographic Network (LD), New England Seismic Network (NE), Cooperative New Madrid Seismic Network (NM) and Penn State Network (PE) provide an unprecedented opportunity to study earthquakes in the stable Eastern North America (ENA).

The initial objective of the USArray component of the EarthScope project was to explore the structure and evolution of North America using continuous recordings from broadband seismometers of TA stations. While research goals of the EarthScope in ENA are still carried out by the EarthScope project, we have begun to look at broad regional scale crust and uppermost mantle structure using receiver function analysis (EARS: EarthScope automated receiver survey) and automated surface wave tomography tools developed during EarthScope project, and report our results on crustal thickness variation and lithosphere-asthenosphere boundary in the eastern US. We report results of our effort to find repeating earthquakes from waveform archives in the Adirondacks, New York and Western Quebec, Canada by employing a waveform cross-correlation technique.