1968 Casiguran earthquake
UTC time | 1968-08-01 20:19:22 |
---|---|
ISC event | 817557 |
USGS-ANSS | ComCat |
Local date | August 2, 1968 |
Local time | 04:19:22 |
Magnitude | 7.3 Mw[1] |
Depth | 25 km (16 mi)[1] |
Epicenter | 16°18′58″N 122°04′01″E / 16.316°N 122.067°ECoordinates: 16°18′58″N 122°04′01″E / 16.316°N 122.067°E[1] |
Type | Thrust[2] |
Areas affected | Philippines |
Max. intensity | IX (Violent)[citation needed]PEIS – VIII (Very Destructive) [3] |
Tsunami | .3 m (1 ft 0 in)[4] |
Foreshocks | 10+[2] |
Casualties | 207–271 dead, 261 injured [4] |
The 1968 Casiguran earthquake occurred on 04:19:22 local time on August 2 with a moment magnitude of 7.3 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[]
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. 268 people were reported to have died during the collapse of the six-story Ruby Tower, located at the corner of Doroteo Jose and Teodora Alonzo Streets in the district of Santa Cruz.[5][a] 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.[7] 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[]
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.[8]
Aftermath and legacy[]
The former location of Ruby Tower in Santa Cruz district is now a memorial hall which stands today.[7][9]
See also[]
Notes[]
References[]
- ^ a b c "M 7.6 - Luzon, Philippines". United States Geological Survey. August 1, 1968. Retrieved August 27, 2017.
- ^ a b Su 1969, p. 459
- ^ "Destructive Earthquakes in the Philippines". phivolcs.dost.gov.ph. PHIVOLCS. Retrieved 17 October 2021.
- ^ a b USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey
- ^ Moya, George P. (July 2, 2014). "When an earthquake hits Metro Manila". Rappler. Retrieved September 23, 2020.
- ^ Ynares, Dr. Jun. "The Ruby Tower". Manila Bulletin. Retrieved September 23, 2020.
- ^ a b Marianne V. Go (December 14, 2006). "Group warns vs substandard construction materials". The Philippine Star. Retrieved September 1, 2012.
- ^ Su 1969, pp. 465–468
- ^ "Of Manila Earthquakes and Ruby Tower". The Urban Roamer. April 27, 2019. Retrieved September 23, 2020.
Sources
- Su, S. S. (1969), "The Luzon earthquake of 1 August 1968: A preliminary report", Bulletin of the Seismological Society of America, 59 (1): 459–472, archived from the original on 23 September 2015, retrieved 9 November 2013
External links[]
- Earthquakes in the Philippines
- 1968 in the Philippines
- 1968 earthquakes
- History of Aurora (province)
- History of Manila