Group B, Poster #090, Earthquake Geology

Active faulting at Lassen NP and surrounding areas

Evelyn H. Usher, & Michael E. Oskin
Poster Image: 

Poster Presentation

2024 SCEC Annual Meeting, Poster #090, SCEC Contribution #13550 VIEW PDF
Recent lidar surveys reveal numerous previously unrecognized active faults within Lassen Volcanic National Park and its surrounding area. The area connects predominantly strike-slip faulting in the northern Walker Lane with extension of the Hat Creek graben and other normal faults of the Modoc Plateau. There may also be a connection between faulting and volcanism at Lassen Peak, but the nature of such connection is not understood. Intrusion could take up some of the extensional strain that elsewhere is accommodated by faulting, and this could influence the density and orientation of faulting locally. Preliminary mapping supports this hypothesis with fault density declining towards Lassen Peak. Continued mapping of key areas of of Lassen Volcanic National Park and surrounding region will be used to determine fault orientations, kinematics and slip rates through a combination of fieldwork and remote mapping. This work aims to further out understanding the relationship between faulting and volcanism and the transition transition from strike-slip faulting to extension in Northern California and its relationship to the evolving Pacific-North America plate boundary