Untitled Document

News Notes
Deep Earth
California’s Moho

In some ways, mountain ranges are like icebergs bobbing in the sea. The tallest icebergs have the largest underwater counterpart and the highest mountains have the deepest crustal roots. The southern Sierra Nevada in California, however, has an anomalously thin crust. Using seismic imaging, geologists have observed that something is missing: the Moho, a seismic discontinuity named after the Croatian seismologist Andrija Mohorovicic, that marks the boundary between the bottom of the crust and the top of the mantle. The research highlights a unique mountain-building process and may help explain the Sierra’s stunning topography.

For the full story, visit or go to the Sept. 2 Web Extra.

Back to top

Untitled Document

Geotimes Home | AGI Home | Information Services | Geoscience Education | Public Policy | Programs | Publications | Careers

© 2022 American Geological Institute. All rights reserved. Any copying, redistribution or retransmission of any of the contents of this service without the express written consent of the American Geological Institute is expressly prohibited. For all electronic copyright requests, visit: