Tree-Ring Lab
Lamont-Doherty Earth Observatory
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The lone Pine Tree

The photo above shows the Lone Pine Canyon Tree, in Wrightwood, California .

This tree grows directly on the San Andreas fault. Due to accelerations and displacement in the earthquake of 1812, the top broke off and the root system was severely damaged. For several years there was no radial growth. When the tree began to recover from the earthquake, two branches started growing in place of the snapped-off top. The forked top is one piece of evidence leading to earthquake induced damage.

The chronology above show the reduced growth of the Lone Pine Tree.

Annual ring widths just before the 1812 event show normal fluctuations in growth. From 1813 (noted by the arrow) until the early 1820s, there was very little growth. Not until the late 1830s does the tree resume somewhat normal growth. This pattern of tree growth confirms the hypothesis that this tree was damaged by the 1812 earthquake.

The photo shows the actual rings from an increment core of the Lone Pine Canyon Tree before and after the 1812 earthquake. Note that normal growth does not being until after the 1830s. This core also shows evidence of the 1857 earthquake in addition too the effects of dry years.

If you are interested in tree-rings and seismic activity, please contact Dr. Gordon Jacoby at

Route 9W, Palisades, New York 10964 Voice: (845) 365-8517 Fax: (845) 365-8152