2011 UseIT Development Group

A major earthquake is characterized by a release of energy from a fault or plate rupture in excess of 100 TJ. Such earthquakes are usually preceded by a short sequence of seemingly unrelated smaller events and followed by an extended sequence of events smaller than the mainshock. If seismicity in a region is high but no mainshock stands out, then the sequence is designated to be an earthquake swarm. These sequences are viewed in short and long time intervals to illustrate the evolution and minutiae of patterns. Worldwide interest in earthquake sequences has greatly increased due to the destruction and ongoing threat of the Tōhouku and Darfield sequences.

The 2011 Undergraduate Studies in Earthquake Information Technology (UseIT) development team was tasked with constructing a seismic sequence visualization system based on SCEC-VDO and GIS. The developers implemented space-time earthquake display functionality as well as surface layers for major infrastructure and statistical maps. The space-time plot allows users to display earthquake sequences temporally while still referencing magnitude and geographic location. Other improvements include a more accurate display of topography and greater compatibility with shapefiles and databases. These advancements will create an informative and easily interpretable display of earthquake sequences, which will improve risk assessment and hazard preparedness.