New analyses of teleseismic body waves from moderate earthquakes in western Argentina demonstrate that active shortening of the Andean foreland occurs on reverse faults extending to 40–50 km depth. Existing crustal‐scale models of foreland deformation invoke thin‐skinned fault geometries, which root into an east‐dipping mid‐crustal décollement. Whereas thin‐skinned thrust sheets...
The Blanco Transform Fault Zone (BTFZ) forms the ~350 km long Pacific–Juan de
Fuca plate boundary between the Gorda and Juan de Fuca ridges. Nearby broadband seismic networks provide a unique framework for a detailed, long-term seismotectonic study of an entire oceanic transform fault (OTF) system. We use regional waveforms...
We use regional broadband seismograms to obtain
seismic moment-tensor solutions of the two September 20, 1993,
Mw =6, Klamath Falls, Oregon earthquakes, their foreshock and
largest aftershocks (MD>3.5). Several sub-groups with internally
consistent solutions indicate activity on several fault segments
and faults. From the estimated moment-tensors and depths of the...
The Explorer region offshore western Canada is a tectonically complex area
surrounded by the Pacific, North America, and Juan de Fuca plates. Existing tectonic
models for the region differ fundamentally. Proposed plate configurations range from
multiple independent plate fragments to an Explorer plate now fused to North America
along the...
Teleseismic body waves from large earthquakes are used to study the downdip
geometry of continental normal faults in the Aegean. Waveform modeling technique together with rigorous statistical tests are applied to put firm bounds on the amount of downdip curvature of these faults and the role of coseismic slip on...