José Faustino Blanco Chía National University of Colombia Geosciences Department

Issue The principal goal is to find the velocity structure in Colombia to improve the location of local earthquakes.

Data The data come from the Colombian National Seismic Network (RSNC), from 1993 to present. Most of the data come from weak earthquakes, M L <5.0. Waveforms recorded using EARTHWORM. Earthquakes located using SEISAN. One velocity model for the whole country.

Colombian National Seismic Network , short period sensors , one broad-band station , 31 new broad band stations

Tectonic context

Geologic terrains in Colombia

Colombia Seismological Stations

Seismicity RSNC

Shallow Seismicity RSNC

Seismicity

Current velocity model

Data

Data

Shallow data

Parameters of choosen events Shallow seismicity < 50 km GAP < 180 Minimum number stations 6 Minumum Local Magnitude 2.0 Total seismos selected 2879

Questions How do we use the data from earthquake nests Bucaramanga, for example? Is it a good idea to use only shallow seismicity? Is it a good idea to use teleseismic data?

THANKS!!!