Poster Number 198
See more from this Division: Topical Sessions
See more from this Session: Oceanic Geohazards: Distribution, Controls, and Risks (Posters)
Abstract:
Offshore of Half Moon Bay, the NNW-trending San Gregorio fault zone consists of two primary strands. The eastern strand, which extends along the trend of the Seal Cove fault, is a continuous and very linear scarp from Pillar Point at least 15 km southward. The scarp has 1 1.5 m of vertical offset, with the west side upthrown. Numerous folds are truncated by this strand. Its sharp surface expression suggests that the eastern strand may currently be the primary active strand. Fold orientations indicate at least three episodes of deformation; the youngest folds trend ESE-WNW and deform older, more north-trending folds as revealed in the seismic profiles and bathymetry. The western strand of the fault zone is not well imaged in the bathymetry but appears in the seismic-reflection data as the edge of a zone of deformation. A minor third strand of the fault appears to separate the two apparently older fold domains.
See more from this Division: Topical Sessions
See more from this Session: Oceanic Geohazards: Distribution, Controls, and Risks (Posters)