segunda-feira, novembro 04, 2013

Há 61 anos ocorreu um dos mais fortes sismos do século XX

The main earthquake struck at 16:58 GMT (04:58 local time) on November 4, 1952. Initially assigned a magnitude of 8.2, the quake was revised to 9.0 Mw in later years. A large tsunami resulted, causing destruction and loss of life around the Kamchatka peninsula and the Kuril Islands. Hawaii was also struck, with estimated damages of up to US$1 million and livestock losses, but no human casualties were recorded. Japan reported no casualties or damage. The tsunami reached as far as Alaska, Chile, and New Zealand.
The hypocentre was located at 52.75°N 159.5°E, at a depth of 30 km. The length of the subduction zone fracture was 600 km. Aftershocks were recorded in an area of approximately 247,000 km2, at depths of between 40 and 60 km. A recent analysis of the tsunami runup distribution based on historical and geological records give some indication as to the slip distribution of the rupture.

View of the Severo-Kurilsk port. In 1952 a whole settlement was located there. The modern town was rebuilt in another place.

1952 Severo-Kurilsk Tsunami was a major tsunami that hit Severo-Kurilsk, Kuril Islands, Sakhalin Oblast, Russian SFSR, USSR, which occurred on 5 November 1952 at about 5 a.m. It led to the destruction of many settlements in Sakhalin Oblast and Kamchatka Oblast, while the main impact struck the town of Severo-Kurilsk. The tsunami was generated by a major earthquake in the Pacific Ocean, 130 km from the shore of Kamchatka, with an estimated magnitude of 9.0. There were three waves about 15-18 m high. After the earthquake the majority of the Severo-Kurilsk citizens fled to the surrounding hills, where they escaped the first wave. However, most of them returned to the town and were killed by the second wave. The third wave was minor. According to the authorities, out of a population of 6,000 people, 2,336 died.
The remaining survivors were evacuated to continental Russia. The settlement was then rebuilt in another location.

NOTA: embora provocando poucos mortos, dada a sua magnitude, este sismo é considerado o 5º com mais magnitude desde que esta é mesurável (fonte: - USGS):


Location Date UTC Magnitude Lat. Long.
1. Chile 1960 05 22 9.5 -38.29 -73.05
2. Prince William Sound, Alaska 1964 03 28 9.2 61.02 -147.65
3. Off the West Coast of Northern Sumatra 2004 12 26 9.1 3.30 95.78
4. Near the East Coast of Honshu, Japan 2011 03 11 9.0 38.322 142.369
5. Kamchatka 1952 11 04 9.0 52.76 160.06
6. Offshore Maule, Chile 2010 02 27 8.8 -35.846 -72.719
7. Off the Coast of Ecuador 1906 01 31 8.8 1.0 -81.5
8. Rat Islands, Alaska 1965 02 04 8.7 51.21 178.50
9. Northern Sumatra, Indonesia 2005 03 28 8.6 2.08 97.01
10. Assam - Tibet 1950 08 15 8.6 28.5 96.5
11. Off the west coast of northern Sumatra 2012 04 11 8.6 2.311 93.063
12. Andreanof Islands, Alaska 1957 03 09 8.6 51.56 -175.39
13. Southern Sumatra, Indonesia 2007 09 12 8.5 -4.438 101.367
14. Banda Sea, Indonesia 1938 02 01 8.5 -5.05 131.62
15. Kamchatka 1923 02 03 8.5 54.0 161.0

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