USGS - science for a changing world

GMEG - Geology, Minerals, Energy, & Geophysics Science Center

BIGFOOT: BIG-storm FOOTprint on California and future hazards

 

 

Surficial Geologic Mapping of Channel Islands National Park

The sea cliffs and coastal lowlands on the five islands comprising Channel Islands National Park (CHIS) (San Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara) are subject to episodic intense wave erosion, storm-induced flooding, tsunamis, as well as long-term sea-level change. Major storm events may result in more extreme degradational and aggradational responses in such areas, and they may trigger landslides and significant mass wasting both in the sea cliffs and on steeper slopes in the island interiors. Furthermore, neotectonic deformation and modern seismicity are concentrated in the Santa Barbara Channel region, including the bordering Channel Islands, with increased attendant uplift and subsidence amounts and rates. Partly as a result of these and other potential geohazards on the islands, a surficial geologic map of CHIS was identified as being needed by the NPS at a GRE scoping meeting in Ventura in 2008.

The main objective of this task is to produce a surficial geologic map of the five-island Channel Islands National Park (CHIS). The mapping will focus on Pleistocene and younger marine terrace, eolian, landslide, colluvial, and fluvial deposits and Quaternary faults and folds. Marine fossils in the deposits will be collected for age dating by U-series, amino-acid, and Sr-isotopic methods.

Bedded eolianite, lithified sandy, calcareous sediment deposited by wind, on Northeastern portion of Santa Rosa Island.

Bedded eolianite, lithified sandy, calcareous sediment deposited by wind, on Northeastern portion of Santa Rosa Island.

 

 
This mapping effort on islands will build on, and collaborate with, recent and current research being conducted on the CCSP-funded "Impacts of Climate Change on Coastal and Eolian Landscapes" project. On-going CCSP-funded work includes obtaining precision ages and elevations of marine terraces to determine accurate uplift rates and sea-level histories, eolian and air-borne dust deposition investigations, and fluvial erosion studies.

Old dip-slip block slide identified by A) arcuate depression in surface morphology

Old dip-slip block slide identified by arcuate depression in surface morphology.

Deformed slide mass over bedded Becher's Bay formation.

Deformed slide mass over bedded Becher's Bay formation

View east along the island-spanning Santa Rosa Island fault.

View east along the island-spanning Santa Rosa Island fault.

Highlights and Key Findings:

In cooperation with Channel Islands National Park, field visits to Santa Rosa Island (SRI) continued structural and geomorphic characterizations of the large SRI fault that transects the entire island. Investigations revealed that the fault has a complex slip history that includes late dip-slip movement that is linked to differential uplift and fluvial dissection and deposition across multiple fault strands.  Participating with Fog Hydrology project, this research aims to understand how landscape degradation influences the soils, hydrology, and biology.

   

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://geomaps.wr.usgs.gov/bigfoot/task1_1.html
Page Contact Information: Webmaster
Page Last Modified: 20-Dec-2016@16:10