Evaluating Rainfall, Landslides, and Weather: Big Sur, California

This page authored by Ana Garcia-Garcia, Monterey Peninsula College, is partly based on previous work from Faculty of the Earth Sciences Department at MPC.
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Summary

In this two-part activity, the students will first test the relationship between precipitation and frequency of mass wasting events. They will research and analyze real local data to investigate and understand landslide potential. They will also work on understanding the link between weather patterns (El Niño) and mass wasting events.

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Learning Goals

  • To test the hypothesis that there is a relationship between precipitation and frequency of mass wasting events
  • To analyze real local data to investigate and understand landslide potential
  • To research records from data repositories.
  • To understand the link between weather patterns (El Niño) and mass wasting events

This activity covers a local common hazard and its risks. The students learn how to find the location of potential landslides and how they are linked to weather.

Context for Use

Basic Geology level. 30 people. Lab activity. After discussing the background data (mass wasting, El Niño weather patterns) in a previous lecture, this activity should take 1h.

Description and Teaching Materials

Part 1 - The students answer a few questions about the rainfall data from 1997-2007 in the local area and how that relates to the number of landslides Big Sur has had. I do give them the data in this lab in a Table(optional to make them go to the CA Department of Water Resources website and find those datasets).

They have to go to that website and find this year's rainfall record and compare it to previous years.

Part 2 - They study a Table that lists years of weak/moderate/strong El Nino and local rainfall for those years. They answer a few questions about their relationship.

Teaching Notes and Tips

  • The tables can be given to students with the word document, as an excel file (better), or if you have lab time, you could make them retrieve the information from the websites (best).
  • I like adding a third part to this lab about local geology and how the types of material affect the mass wasting movements:
Part 3 - The type of landslide will be influenced by the type of material that is involved. For the same conditions, it is obvious that a weaker type of rock moves easier than a more resistant one.

9. Browse in the 2010 interactive California map and choose a section of Big Sur and explain briefly its geology.(https://earthquake.usgs.gov/earthquakes/map/?extent=7.71099,-144.22852&extent=60.02095,-45.79102)

10. GO to the CSG report 185 link, find your chosen section, and see what type of geological map and landslide map has been produced for that area. Does it make sense to you? how many potential landslides are there?

Assessment

This activity is done in groups. After they finish, each group has to explain each other their answers and what they found out/learn. This always lead to discussion and personal stories(this is a common rock slide/mudslide area and a frequent highway we all drive through). After the group discussion they all should have attained the goals for this lab and answered all questions right. They turn in the labs and I grade them. In most cases, they get the maximum grade.

References and Resources

Already in the lab:

Reports Big Sur Landslides:
C.J. Wills, M.W. Manson, K.D. Brown, C.W. Davenport and C.J. Domrose, 2001, Special Report 185 - Landslides in the Highway 1 Corridor: Geology and Slope Stability along the Big Sur Coast between Point Lobos and San Carpoforo Creek, Monterey and San Luis Obispo Counties, California. California Geological Survey, 40 pp. http://www.conservation.ca.gov/cgs/Documents/Landslides/Caltrans/SR_185/CT001mon%20Report.pdf

Estimated Sediment Yield from Coastal Landslides and Active Slope Distribution Along the Big Sur Coast, Monterey and San Luis Obispo Counties, California, from the SIMoN Project at http://sanctuarysimon.org/projects/100243/estimated-sediment-yield-from-coastal-landslides-and-active-slope-distribution-along-the-big-sur-coast,-monterey-and-san-luis-obispo-counties,-california-- (offline)

El Niño:
NOAA El Niño/ENSO Discussion at http://www.ncdc.noaa.gov/teleconnections/enso/enso-tech.php
NOAA's El Niño page at https://www.pmel.noaa.gov/elnino/

Landslides Local News:
http://www.noozhawk.com/article/032611_big_sur_landslides/
http://www.mercurynews.com/ci_17638872

Geology:
Department of Conservation of California Geological Survey. Regional Geologic Hazards and Mapping Program. Pdf of Special Report 185, geological maps and landslide maps can be downloaded at http://www.conservation.ca.gov/cgs/rghm/landslides/Pages/Index.aspx

CSG Interactive California geological map at https://earthquake.usgs.gov/earthquakes/map/?extent=7.71099,-144.22852&extent=60.02095,-45.79102