1. Home
  2. Education
  3. Geology

Echelon Cracks at Lake Temescal

The Hayward Fault in Oakland, California
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]


This set of echelon cracks at Lake Temescal Regional Recreation Area runs straight to an interpretive sign pointing out their significance. Fault traces are rarely this obvious. Moreover, this trace is only one element of a wider complex of cracks and slivers tens to hundreds of meters wide that makes up the fault zone. Indeed, the Hayward fault is only one element of a complex plate boundary that includes the San Andreas fault and several other major faults.

Under this spot, the U.S. Geological Survey has emplaced a creepmeter across the fault trace. That is a wire strung between two concrete piers in an underground vault isolated from the surface environment. Its data is fed to a satellite link and onto the Web.

Start | < Back | Next >

Photo (c) 2005 Fleur Helsingor, reproduced by permission. (fair use policy)

Explore Geology

About.com Special Features

A Smarter Future

Tips that will help finance your education, excel in the classroom, and advance your career. More >

How to Ace the GRE

Being well prepared is the first step; here are more essential suggestions. More >

  1. Home
  2. Education
  3. Geology

©2009 About.com, a part of The New York Times Company.

All rights reserved.