2024-06-21 Discovery Bay Tsunami Evidence Field Trip

Examine Discovery Bay’s Past Tsunami Record Using Two Contrasting Evidential Methods

There are at least two salient features of Pacific Northwest history:  an extremely active geologic past, coupled with a region inhabited by indigenous peoples since “time immemorial”.

These two features share common ground at Discovery Bay on the Quimper Peninsula of Washington State. Many tsunamis have occurred at this bay over at least the past 3000 years, during which time the area was concurrently inhabited by indigenous peoples.

This field trip examines the geologic and anthropological evidence of the occurrence of multiple tsunamis in Discovery Bay. Our field trip leaders, Dr. Carrie Garrison-Leavy (geologist) and Dr. Alexandra Peck (anthropologist), are active researchers in their respective fields, which are specific to this topic. They lead us through an examination of the possible link between tidal marsh tsunami sedimentation and indigenous oral histories as contrasting evidential methods of recording tsunami history.

About the Speakers

Dr. Carrie Garrison-Laney is a Coastal Hazards Specialist at Washington Sea Grant and a liaison to the NOAA Center for Tsunami Research. A focus of Carrie’s research has been the age and distribution of paleo-tsunami deposits with lessons learned from historical events. She earned her PhD from the University of Washington.

Dr. Alexandra Peck is professor and Audain Chair in Historical Indigenous Art at the University of British Columbia. Trained in archaeology, her research explores pre-colonial Native life, cultural change, and social interactions on the Olympic Peninsula. With extensive academic publications, she is also co-editor of Archaeology in Washington.

Carrie suggests for the wetland portion of the trip:

Wetland participants must come equipped with at least knee-high boots since the tsunami sediments are exposed in a tidal marsh. This will be messy but fun!!!!

 

2024-03-23 Brian Sherrod — New Findings on Earthquakes of Salish Lowland with Tree Analysis

We enjoyed hearing in-person USGS geologist, Dr. Brian Sherrod, on February 24, 2024 and by Zoom March 23.

THE LECTURE:  High-resolution dating of a multi-fault earthquake and earthquake recurrence in the Salish Lowland

See Sept. 2023 Science Advances article: https://www.science.org/doi/10.1126/sciadv.adh4973

Dr. Brian Sherrod discusses new evidence for a multi-fault rupture. This rupture occurred along the Seattle (SFZ) and Saddle Mountain (SM) faults in the winter of 923-924 CE. He presents new evidence for a proto-historic earthquake on the Seattle fault (in the 1830s), and he talks about recurrence of large earthquakes in the Salish Lowland. He employs photographs, USGS mapping, lidar measurements, charts, and graphs to elaborate his points. Brian is a master story-teller, and his lecture will explain how this important event was detected.

For a complete version of the research paper:  Black, Pearl, et al., 2023, A mulitfault earthquake threat for the Seattle metropolitan region revealed by mass tree mortality:  Science Advances 9, Sept. 2023

THE SPEAKER:

Dr. Brian Sherrod is a Research Geologist and Pacific Northwest Regional Coordinator for the USGS Earthquake Hazards Program, based in the Department of Earth and Space Sciences at the University of Washington.

He received his BS in Geology from James Madison University in Virginia, his MS in Geology from the University of Pittsburg, Pennsylvania, and his PhD in Geological Sciences from the University of Washington. His main area of research is paleo-seismology:  finding evidence of past earthquakes in the Pacific Northwest using geological records. Much of his work uses lidar. His recent projects include looking for evidence of surface rupture along faults in central and western Washington, coastal uplift, and subsidence along faults in the northern Salish Lowland.

 

 

2023-07 Tamanowas and Peregrine Rocks field guide

For the Tamanowas and Peregrine Rocks field trip, use the link below to download the guidebook.  Please print a copy for your use on the trip: the figures and photographs will be particularly useful.

For location and historical info about the Jefferson county site –>

For 2022 field trip report –>

Click here:  Tamanowas Rock guidebook

If you have technical or logistical questions, contact webmaster@quimpergeology.org