Guide to the California Coastal Cliff Erosion Viewer

The online viewer provides information on cliff face (averaged over the cliff profile) and cliff top retreat rates across the state for two monitoring periods: 1998 to 2009-2011 and 2009-2011 to 2016. The analyses were performed using airborne light detection and ranging (LiDAR) datasets. Retreat rates were calculated at an alongshore resolution of five meters then grouped into larger coastal sections.

The viewer shows cliff retreat rates from regional to local levels at scales of 50, 10, 5 and 1 kilometer alongshore zoom levels. The displayed point is located in the middle of the area it represents. The point color and size indicate cliff face and top retreat rates, respectively, between 2009-2011 and 2016. Use the icon in the top right corner to switch between scales.


Additional details are displayed when clicking the individual points including: alongshore location (Start/End), and retreat statistics for the two monitoring epochs. Data for much of northern California was only available for the later epoch [3]. Locations of data points are referenced by their distance from the US/Mexico border thus longshore locations 0 and 1646 km represent the Mexico and Oregon borders, respectively. Click the plot in the popup to enlarge it on a new page.



[1] Young, A.P. 2018. Decadal-scale coastal cliff retreat in southern and central California. Geomorphology 300, 164–175.

[2] Swirad Z.M. & Young A.P. 2021. Automating coastal cliff erosion measurements from large-area LiDAR datasets in California, USA. Geomorphology 389: 107799.

[3] Swirad Z.M. & Young A.P. 2022. Spatial and temporal trends in California coastal cliff retreat. Geomorphology 412: 108318.
[4] Swirad Z.M. & Young A.P. 2022. CliffDelineaTool v1.2.0: an algorithm for identifying coastal cliff base and top positions. Geoscientific Model Development 15: 1499-1512.