| 1968 Casiguran earthquake | |
| Timestamp: | 1968-08-01 20:19:22 |
| Isc-Event: | 817557 |
| Anss-Url: | iscgem817557 |
| Local-Time: | 04:19:22 |
| Map: | 1968 Casiguran earthquake.jpg |
| Magnitude: | 7.6 7.3 Ms[1] |
| Depth: | 25km (16miles) |
| Location: | 16.316°N 122.067°W |
| Type: | Thrust |
| Countries Affected: | Philippines |
| Tsunami: | 0.3m (01feet) |
| Intensity: | [2] |
| Foreshocks: | 10+ |
| Casualties: | 207–271 dead, 261 injured |
The 1968 Casiguran earthquake occurred on 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.
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.[3] 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 the use of poor-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.[5]
The aftershock sequence throughout the month of August included many moderate shocks, including fifteen over 5.0 . The strongest of these occurred on August 3 with a 5.9 event that produced intensities of III–IV in Manila.
The former location of Ruby Tower in Santa Cruz district is now a memorial hall which stands today.[4] [6]
Sources