Geologic observations of the northern boundary of the Caribbean plate across central America as seen by Seasat and SIR-A

The radar data analyzed here extend from the Amatique Bay (Golfo de Honduras) in the northeast to the Pacific Ocean (Puenta Remedios) in the southwest. Space Shuttle Imaging Radar (SIR-A) data-take 18 overlaps the principal part of the Seasat mosaic. SIR-A data make possible more observations over the Central American Cordillera, where strong layover limited the amount of information obtained by Seasat. The radar coverage delineates the principal strike-slip faults of the region (Cuilco-Chixoy-Polochic, Motagua and Jocotan), which have acted as the Caribbean-Americas plate boundary. It also demarcates volcanic terranes related to subduction of the Cocos Plate under the Caribbean Plate. Within pumice fields of the Tertiary volcanic belt, the use of two Seasat look directions (rev 759 and rev 1211), in conjunction with SIR-A data, makes possible some rock discrimination.