The enormous mining-induced Naga City landslide in Cebu, the Philippines

Yesterday an enormous landslide occurred at Naga City in Cebu, the Philippines.  This was an extraordinary event, without doubt one of the largest mining-induced landslides in recent years.  Whilst it has garnered very little publicity outside the Philippines, this was an unusual landslide:-

The Naga City landslide in the Philippines.  Image via Youtube

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Asian Policy Press has an excellent gallery of images, including this one:-

Overview of the Naga City landslide. Image via Asian Policy Press. 

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As the image above shows, the margins of the landslide buried houses built around the quarry.  To date it has been confirmed that 21 people were killed; a further 74 are reported to be missing.

There is an interesting video on Youtube showing the landslide.  The first part appears to have been shot ahead of the failure, and highlights multiple tension cracks, some looking very fresh.  The images appear to correspond to the landscape of the failed area, and the shots that include the quarry are credible, although I cannot guarantee that they are from the same site.  The second part shows grainy but amazing footage of the landslide in motion.  The third part shows the  aftermath of the landslide, shot from the air.

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Google Earth has good imagery of the site of the landslide, taken in 2017:-

Google Earth imagery of the site of the Naga City landslide.

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Whilst Planet Labs have an image captured yesterday after the landslide:-

Planet Labs PlanetScope image showing the aftermath of the Naga City landslide. Image collected on 21st September 2018, used with permission.

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The imagery suggests that there can be little doubt that this slide was associated with the mining activity, although the final trigger may have been rainfall-related.  One is left wondering how such a disaster can occur if, as seems to be the case, the hillside was showing multiple signs of distress.  This is, of course, the second destructive landslide in the Philippines in a week.

Reference

Planet Team (2018). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://api.planet.com