Coast Geological Society

Ventura, California

Please Join CGS on Tuesday November 19th, 2019

Ed Keller, Ph.D., Professor at U.C. Santa Barbara, and
 Chandler Adamaitis, M.Sc. Candidate at U.C. Santa Barbara, will present their talk titled:

Montecito Debris Flows of January 9, 2018 and flow chronology over the past ~100,000 years


The ~ M6 Montecito Debris flow of January 9, 2018 was a tightly linked event wildfire – debris flow event that took 23 lives and damaged or destroyed several hundred homes Relative flow chronology, based on boulder weathering, with limited numerical dating is used to correlate paths of prehistoric debris flows. Nearly the entire community on the piedmont Montecito and Santa Barbara is impacted by debris flows that range in age from the late Pleistocene to present. Topography of the upper piedmont is significantly affected by the south -side -up reverse Mission Ridge fault system (MRFS). Examination of weathering rinds of the older Pleistocene debris flows confirm that the Rattlesnake Creek-Mission Ridge debris flow is folded over the ridge.  Over time faulting and lateral propagation linked to uplift of marine terraces (uplift rate of ~ 0.5 to 1 m/ky) significantly altered debris flow paths, moving exposure to the hazard ~ 700m west. Paths of debris flows in Montecito are maintained across the relatively low folds and young fault scarps of the MRFS. The flow (~ 2 m thick) consists of a lower boulder layer with mud tail on top) is below an uplifted late Holocene marine wave-cut platform (earthquake terrace) with a prehistoric native American site is at the surface. The main conclusion is that debris flows interact significantly with the Santa Barbara and Montecito landscape, modified by uplift, folding and faulting to change flow paths and thus the exposure of people and property to the hazard.

Edward Keller, Ph.D.


Ed Keller is a professor at  the University of California, Santa Barbara in Environmental Studies and Department of Earth Science. His research efforts are divided into several areas of surface processes: the study of stream and river form and process and studies of Quaternary stratigraphy and tectonics as they relate to earthquake hazard, landslides, active folding, and mountain building. 

Check out Ed's website HERE

Chandler Adamaitis


Chandler Adamaitis received her BS from the Ohio State University in 2017 in Earth Science. Her research interests are in Earth Processes, particularly natural hazards. She is in her second year of a MS program at UC Santa Barbara investigating the chronology of high magnitude debris flows of Santa Barbara.


The monthly CGS meeting is held at the Poinsettia Pavilion in Ventura!

Meeting Schedule:

6:00 - 7:00 PM: Social Hour - Snacks and Beverages 

7:00 - 7:30 PM: Dinner Service

7:30 - 8:00 PM: Announcements & Raffle

8:00 - 9:00 PM:  Main Presentation

CGS is proud to be affiliated with the PSAAPG