How the Japan Quake Triggered Aftershocks

Lifes Litle Mysteries www.LifesLittleMysteries.com Japan Quakes Cause Faults to Strain or Relax An earthquake alters the stress along the fault lines in its vicinity. The map below shows the way in which Japan's magnitude-9.0 earthquake on March 11 – and the 7.9 aftershock that followed it CHINA RUSSIA AREA OF MAR less than an hour later – affected the stress in the region. Areas of increased stress are shown in red and relaxed areas are shown in blue. N. KOREA Sendai (KOREA TOKYO, INCREASED HAZARD 200 miles, MAGNITUDE 9.0 MARCH 11, 2011 DECREASED HAZARD 200 km Remote M=6.6. aftershock (March 11) - Kanto fragment, M-9.0 Unruptured megathrust Southem edge of rupture Sagami trough megathrust SOURCES: UNITED STATES GEOLOGICAL SURVEY, NATURE GEOSCIENCE http://supersites.earthobservations.org/Stein+Toda_Sendai.jpg KARL TATE / lifeslittlemysteries.com