1968 Casiguran earthquake

From Wikipedia, the free encyclopedia
Jump to: navigation, search
1968 Casiguran earthquake
Origin time 20:19:22 UTC on August 1 [1]
Magnitude 7.6 Mw [1]
Depth 25 km (16 mi) [1]
Epicenter 16°19′N 122°04′E / 16.32°N 122.07°E / 16.32; 122.07Coordinates: 16°19′N 122°04′E / 16.32°N 122.07°E / 16.32; 122.07 [1]
Type Thrust [2]
Areas affected Philippines
Max. intensity IX (Violent) [3]
Tsunami .3 m (1 ft 0 in) [3]
Foreshocks 10+ [2]
Casualties 207–271 dead, 261 injured [3]

The 1968 Casiguran earthquake occurred on 04:19:22 local time on August 2 with a moment magnitude of 7.6 and a maximum Mercalli intensity of IX (Violent). The thrust earthquake's epicenter was in Casiguran, Quezon (now part of Aurora province). A small non-destructive tsunami was generated and at least 207 people were killed. The majority of the deaths occurred in the collapse of a six-story building in Manila.

Damage[edit]

In Manila, many structures that suffered severe damage had been built near the mouth of the Pasig River on huge alluvial deposits. A number of buildings were damaged beyond repair while others only suffered cosmetic damage. Several hundred people died during the collapse of the six-story Ruby Tower, located in the district of Binondo. The entire building, save for a portion of the first and second floors at its northern end, was destroyed. Allegations of poor design and construction, as well as use of low-quality building materials, arose.[4] In the District of Santa Ana, one person was injured by debris from a damaged apartment building.

Two more people from Aurora sub province and Pampanga died as a direct result of the quake. Around the town of Casiguran, there were several reports of landslides, the most destructive one at Casiguran Bay.

Aftershocks[edit]

The aftershock sequence throughout the month of August included many moderate shocks, including fifteen over 5.0 Mb. The strongest of these occurred on August 3 with a 5.9 Ms event that produced intensities of III–IV in Manila.[5]

References[edit]

  1. ^ a b c d ISC (2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre 
  2. ^ a b Su 1969, p. 459
  3. ^ a b c USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey 
  4. ^ Marianne V. Go (December 14, 2006). "Group warns vs substandard construction materials". The Philippine Star. Retrieved September 1, 2012. 
  5. ^ Su 1969, pp. 465–468

Sources

External links[edit]