Figure 1. Large Costa Rica plate interface earthquakes and subducting topographic features that may have influenced these earthquakes. Left: Earthquake rupture area and bathymetry. Middle: Cross sections through the bathymetry data. Right: Source time functions for the 3 large earthquakes. Rupture areas and source time function complexity are related to the complexity of the subducting topographic features opposite the earthquake location, with the fairly simple 1990 and 1999 earthquakes related to the simpler Fisher Seamount Group and Quepos Plateau. The more complicated rupture of the 1983 earthquake broke the lateral extent of the Cocos Ridge. From Bilek and Lay (2002).