Lesson 15: California's Coast

Point Reyes headland (photo by M. Miller)Perhaps more than by any other feature, California is defined by its coastline. Although some parts of the state's coast remain much as they were when European settlers arrived during the early 19th century (Point Reyes headland, right) many others have been altered dramatically by the wetland modification and construction necessary to accomodate the growth of coastal populations. This chapter explores how several natural processes— from wave erosion and longshore transport to tectonic uplift and sea-level rise—continue to shape the state's coast. These processes also create potential hazards for coastal residents that are likely to impact almost everone in the state—whether you live in a coastal county or pay higher insurance and public safety costs to assist those who do—in the years to come. Finally, proposals to drill for oil and natural gas off the state's shore are currently being debated in an effort to balance economic and environmental concerns. Although we will not consider the pros and cons of these proposals directly, we will look at the geologic origins of such deposits next week when we explore the Transverse Ranges.

In chapter 15 Harden reviews coastal processes such as wave erosion and longshore transport and explores how California's active tectonics interact with these processes to produce both submergent and emergent coastlines as well as marine terraces. In this week's exercise you'll have a chance to assess the potential effects of a tsunami on a coastal town which, as recent events in Japan remind us, is a potential threat to any coastal area.

As you read about California's coast be sure to take careful notes on the topics covered by the learning objectives below. As during previous weeks, you'll find that writing out key facts in your own words or making neatly labeled drawings will help you better understand the significance of what you've read and spot any gaps in your knowledge. Don't hesitate to post any questions you have to the Discussion Board so that your classmates or I can help you figure them out. Having good notes will also make it easier for you to review for this week's quiz and and access what you've learned when you want to refer back to it for future assignments. Be sure that you are prepared to meet the learning objectives outlined below before you move on to the quiz at the bottom of the page.

Weekly Learning Objectives

Upon successful completion of this week's lesson, a student is expected to be able to:

Reading and Browsing Assignment

Exercise 15: Tsunami and Storm Surge (Due by 9:00 AM on 2-May-2011)

Earthquakes throughout the Pacific Ocean and landslides on oceanic islands like Hawaii have the potential to generate tsunamis that could reach the California coast. In order to learn a little more about this threat as well as that potentially posed by surges from tropical storms moving north from Baja, please load you Hazard City CD and work through version 3 of the Tsunami/Storm Surge project. This is one of the more straightforward Hazard City assignments, and it will probably take you about an hour to complete. Be sure to jot down any notes on the procedure you followed and have the report form printed and filled-in before you go to the Tasks and Tests area of the Etudes site to complete Exercise 15. Also, note the following: (1) to calculate the speed of the tsunamis I simply printed the page containing the map and made my measurements right on the paper—doing so, I obtained a value between 380 and 390 mph for the Valdez tsunami rather than the value given by the authors; and (2) people's homes are evenly distributed throughout Ocean Village. Finally, there are only six questions on this week's exercise so, to make the total come out to 10 points each will be worth 1.67 points.

Quiz 15: California's Coast (Due by 9:00 AM on 2-May-2011.)

After you feel you have met the learning outcomes outlined above please complete Quiz 15 in the Etudes "Assignments, Tests, and Surveys" tool. There are ten questions about the California's coast and the processes that are shaping it, and each is worth one point. If you can answer all of them correctly it means that you know your way around the coastal geology pretty well and are ready to start learning about California's Transverse Ranges next week. Like all of our weekly quizzes, this one is timed (you'll have 30 minutes) and must be completed in one "sitting". (That is, you will only be granted access once.) So, be sure you're ready to complete your quiz when you start it—and be sure you're using Firefox. Good luck.