Lake Toba seismic network, Sumatra, Indonesia

The Toba caldera is located in
north Sumatra, Indonesia. It is part of the volcanic arc associated with
the subduction of the Australian Plate beneath the Southeast-Asian
Plate. The subduction zone, and the Sumatra Fault, a right lateral
strike-slip fault which marks the plate boundary, are seismically
active. In order to investigate the volcano-related seismic activity and
image the volcano related structures (i.e. a potential magma chamber)
using ambient noise techniques a dense seismic network was installed
around Lake Toba between May and October 2008. The network, deployed
within a German-Indonesian cooperation, comprised 42 continuously
recording seismic stations equipped with three-component, short-period
seismic sensors with 1 Hz natural frequency. The GPS-synchronised data
loggers recorded at 100 samples per second for the experiment's time span
of 6 months. During this time period local and regional seismicity was
recorded. The array of stations covers an area of approx. 150 by 200 km
with inter-station distances of about 20 km. The station distribution is
quite irregular due to the difficult environmental conditions. Data from
all stations are freely available from the GFZ seismological data
archive.