28 July 2022

Landslides from the 27 July 2022 M=7.0 earthquake in Abra, Philippines

Posted by Dave Petley

Landslides from the 27 July 2022 earthquake in Abra, Philippines

On 27 July 2022 a M=7.0 earthquake struck Abra Province in the northern part of Philippines, with the epicentre being located close to Tayum.  Fortunately, this is a lightly populated part of the country, but the Manilla Times is reporting at least five fatalities.  The shallow depth of this earthquake (the USGS reports it as 10 km) and the hilly terrain means that landslides are inevitable, and indeed have been widely reported.

The USGS attempts to model likely landslide probability from large earthquakes.  Their simulation appears to estimate an extensive area with high landslide probability:-

A USGS estimate of landslide probability from the 27 July 2022 earthquake in the Philippines.

A USGS estimate of landslide probability from the 27 July 2022 earthquake in the Philippines.

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Some reports of landslides have already emerged.  The Manila Times reports two fatalities from landslides:-

“[A] person was killed when boulders smashed into the building site where he was working in Kalinga province, police said. Six other workers were injured.  Police said an elderly woman in Suyo municipality in Ilocos Sur province suffered fatal injuries after she was buried by a landslide while out walking.”

Meanwhile, the Manila Bulletin reports a further fatal landslide in Benguet:

“A 32-year old laborer died after he was buried in a landslide that was triggered by the 7.0 magnitude earthquake in Tuba, Benguet.  The victim was identified as Resty Emperador Tavas, a native of Pugo La Union, and a stay-in Laborer at M.A. Camilo Construction, Sitio Bayacsan, Taloy Sur, Tuba.   Police Capt. Marnie Abellanida, spokesperson of the Police Regional Office-Cordillera Administrative Region, said Tavas’ coworkers survived the landslide that occurred at around 8:45 a.m. on Wednesday, July 27.”

Meanwhile, some images of landslides have emerged:-

A landslide blocking a road on the Halsema Highway near to Bontoc.

A landslide blocking a road on the Halsema Highway near to Bontoc. Image released by the The Mountain Province Disaster Risk Reduction Management Office.

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AP has released this very dramatic image of a rockfall in Bauko, Mountain Province:-

A landslide occurring at Bauko in the aftermath of the 27 July 2022 earthquake in Philippines.

A landslide occurring at Bauko in the aftermath of the 27 July 2022 earthquake in Philippines. Image by Harley Palangchao / AP.

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It is likely that there will be many more landslides in the upland areas, and that a further round of landslides will be triggered in the first heavy rainfall event following the earthquake.