1968 Casiguran earthquake

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1968 Casiguran earthquake
1968 Casiguran earthquake.jpg
UTC time1968-08-01 20:19:22
ISC event817557
USGS-ANSSComCat
Local dateAugust 2, 1968 (1968-08-02)
Local time04:19:22
Magnitude7.6 Mw[1]
Depth25 km (16 mi)[1]
Epicenter16°18′58″N 122°04′01″E / 16.316°N 122.067°E / 16.316; 122.067Coordinates: 16°18′58″N 122°04′01″E / 16.316°N 122.067°E / 16.316; 122.067[1]
TypeThrust[2]
Areas affectedPhilippines
Max. intensityIX (Violent)[3]
Tsunami.3 m (1 ft 0 in)[3]
Foreshocks10+[2]
Casualties207–271 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]

Aftermath and legacy[edit]

The former Ruby Tower in Binondo, Manila is now a memorial hall which stands today.[citation needed]

See also[edit]

References[edit]

  1. ^ a b c "M 7.6 - Luzon, Philippines". United States Geological Survey. August 1, 1968. Retrieved August 27, 2017.
  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]