 | |
| UTC time | 2019-07-09 12:36:58 |
|---|---|
| USGS-ANSS | ComCat |
| Local date | July 09, 2019 |
| Local time | 8:36:58 PM PST |
| Duration | 20-30 sec |
| Magnitude | Mw 5.6 |
| Depth | 10.0 km |
| Fault | Makilala Fault |
| Type | strike-slip |
| Total damage | A grand total of 106 Schools, 119 Houses, and 14 other Infrastructures damaged after the strong shaking. |
| Max. intensity | MMI VI (Strong) |
| Tsunami | None |
| Landslides | None |
| Foreshocks | None |
| Aftershocks | Mw 5.3, two 4.9's, 4.8 and 4.1 |
| Casualties | 1 dead, 3 injured |
On July 09 2019; 8:36 PM (PST) An Mw 5.6 earthquake jolted the province of North Cotabato, Davao del Sur, and other nearby provinces. NDRRMC reported 1 dead, 3 injured in Makilala after the earthquake″, and a total of 164 Families were affected in Cotabato Province. The ground-shaking rperceived a Maximum Intensity of VI (Strong) in the Modified Mercalli Intensity Scale (MMI) ; near the epicenter of the earthquake (8 km W of Makilala, Cotabato)″. A grand total of 106 Schools, 119 Houses, and 14 other Infrastructures damaged after the strong shaking″
Tectonic Setting
editThe Philippines islands were formed in evolutionary processes involving subductions, collisions, and strike-slip faulting. Earthquakes are frequent there as a result of collision processes between the Philippine Sea Plate (PSP) and the Sunda Plate (SP). The slip convergence between PSP and the SP boundary is obliquely accommodated by the Philippine fault system, which is a major left-lateral strike-slip fault system . The Philippine fault has been slipping at a rate of 33 ± 11 mm/yr in the northern and central Leyte sections. The southern part of the Philippine fault is mainly located in eastern Mindanao and constitutes a complex fault system with discrete strands and splays. Mindanao island is located on the complex collision boundary between the SP and the PSP. Some parts of the convergence between these plates are consumed by the Philippine fault and subduction at the Cotabato trench . Some other parts of the convergence are accommodated by the fault system in Mindanao, and a series of strike-slip faults have developed. The Mindanao earthquake Mw 5.6 occurred in a region within a faulting zone known as the Cotabato fault system, which is a seismically active region due to the presence of several active faults, including the NW-SE trending Makilala-Malungon, M'lang, North and South Columbio and Tangbulan faults, and the SW-NE trending Makilala and Balabag faults. These faults may work with subduction zones to accommodate different components of regional tectonic strain in the slip partitioning system caused by the relative motion between the PSP and SP. Characterizing the geometrical complexity of these source faults has great significance for understanding the seismotectonic implications of the large earthquakes occurring in Mindanao [1]
Earthquake
editThe Earthquake was recorded as Mw 5.6 in PHIVOLCS and EMSC with a shallow depth of 10km. The epicenter of the said earthquake was located in 06.83°N, 125.02°E - 016 km S 30° W of Makilala (North Cotabato).
The Maximun Intensity was recorded as VI in the Modified Mercalli Intensity Scale (MMI) and also on PHIVOLCS Earthquake Intensity Scale (PEIS). The Focal Mechanism indicated that the Makilala Fault moved strike-slip.
There were moderately strong aftershocks ranging Magnitude 4.0 +, yet there were no foreshocks before the event. Strongest aftershock rock Cotabato and Davao del Sur the day after the main event. It was Mw 5.3 by USGS and Mw 5.0 by PHIVOLCS; It perceived as an Intensity V (Moderately Strong) earthquake in the PEIS and MMI of VI by USGS. Many thought it was another seperate event but therefore it was only a moderately strong aftershock. In fact, this was the first strong earthquake that happened in Cotabato and Davao del Sur for the past years.
Damage and Casualties
edit
The place where the most perceived damage was in the small town of Makilala, Cotabato (The epicenter of the event), which more than 100 homes were damaged and whereas 1 died and 3 injured after the quake on the night of July 09 2019; 8:36 PM PST. There was also damage in a nearby City, Kidapawan City. Most Infrastructure and homes were partially damaged in the City of Kidapawan, same for Davao del sur (Magsaysay, Matanao, Bansalan, and Digos City). Tulunan, M'lang, Antipas, and Matalam Cotabato. Central Mindanao was most affected in the earthquake. A grand total of 106 Schools, 119 Houses, and 14 other Infrastructures damaged after the strong shaking″ Davao City didnt have much damage.
References
edit1. https://earthquake.usgs.gov/earthquakes/eventpage/us70004fsk/executive
- USGS on the July 09 2019 Makilala Earthquake
- NDDRMC REPORT AFTER THE EARTHQUAKE
3. a. https://www.phivolcs.dost.gov.ph/index.php/earthquake/earthquake-information3
b. https://www.phivolcs.dost.gov.ph/index.php/earthquake/earthquake-information3
- PHIVOLCS earthquake report on the month of July year 2019