Volatiles and Fluids in Subduction Zones

Local Earthquake Tomography - Costa Rica & Nicaragua

Several amphibious networks were installed in Costa Rica and Nicaragua:

• JACO (04/2002-10/2002)
• QUEPOS (10/2002 - 04/2003)
• TOMO (10/2005 - 06/2006)

The network JACO and QUEPOS were located on- and offshore the pacific coast of central Costa Rica. The combined tomography uses the arrival times of about 2000 earthquakes at 129 stations including also stations from the national seismological network RSN of Costa Rica and provides highly accurate located events and a 3D-model for the P- and S-velocity.

The following features can be recognized:

• The seimogenic zone at the coast of Costa Rica.
• The subducting slab reaches down to 80 km.
• The dip angle of the slab varies from the north to the south.
• The velocity model shows features which can be related to geological structures.

The network TOMO was located on- and offshore the pacific coast of northern part of Nicoya and the Isthmus of Nicaragua. Over 3000 earthquake were recorded. The seismogenic zone is located at the continental margin. About 1000 earthquake recorded at more than 14 stations are used to set up the data base for the tomography.

For further information, see Nilay Dinc's PhD thesis and Ivonne Aden-Arroyo's PhD thesis.