by Acad. Nikolai LAVEROV, RAS Vice-President; Leopold LOBKOVSKY, Dr. Sc. (Phys. & Math.), Boris BARANOV, Cand. Sc. (Geol. & Mineral.), Shirshov Institute of Oceanology, RAS; Raisa MAZOVA, Cand. Sc. (Phys. & Math.), Nizhni Novgorod State Technical University; Boris KARP, Cand. Sc. (Geol. & Mineral.), llychev Pacific Oceanological Institute, RAS Far Eastern Branch
In the wake of a disaster that hit Sumatra in December 2004 the world scientific community became conscious of the inadequacy of the present ideas about the most probable sites of great earthquakes and tsunami waves. The long "lull" in the northern stretch of the Sunda island arc came as a warning about the forthcoming natural calamity. That is why the present "silence" in the central part of the Kurile-Kamchatka arc may be a bad omen and calls for non-stop monitoring so as to come up with a reliable intermediate-term forecast for several years.
Three great earthquakes occurred along the boundary of the Indo-Australian and Eurasian plates from December 2004 to July 2005. Their epicenters are marked by asterisks, source areas (200 - 1,300 km) - by yellow ovals, plate boundaries-by red lines; the direction of the Indo-Australian plate's movement relative to the Sunda subduction zone-by arrows.
The northern tip of the Island of Sumatra, which is a part of the Sunda island arc (festoon islands) of the East Indies, or Malay Archipelago, and the adjacent area became a scene of a disastrous earthquake on December 26, 2004*. The initial shock was tremendous indeed, so much so that thousands of kilometers away from the epicenter the surface of Sri Lanka (south of the Indian subcontinent) felt the impact-tremors with an amplitude of more than 9 cm continued for sixty seconds, while 1 cm displacements caused by long-period surface seismic waves were registered on the entire surface of our planet. The amount of energy liberated thereby happened to be equal ... Read more