The Lanai Earthquake of February 1871

Abstract

From an extensive compilation of the reported effects of the large Hawaiian earthquake of February 1871, it is concluded that the earthquake occurred at 22:11 on 19 February Honolulu local time (08:42.5 on 20 February Greenwich time); that its epicenter was probably south of Lanai within 60 km of 20.8º N, 157.0 W; and that it had a Richter magnitude of 7.0 + 0.5. Considering its probable epicentral location, it seems appropriately referred to as the Lanai earthquake. Probable average intensities of the earthquake on the Modified Mercalli scale are estimated at IX on Lanai, VII to IX on East Molokai, XI to VIII on Maul; IV to VI on Hawaii; VI to VII on Oahu; V on Kauai; and IV on Niihau.