Deadly landslides in Philippines

Sentinel-2 MSI acquired on 24 June 2018 at 02:23:31 UTC
Sentinel-3 SLSTR RBT acquired on 12 September 2018 from 00:53:26 to 00:56:26 UTC
Sentinel-1 CSAR IW acquired on 12 September 2018 at 21:31:00 UTC
Sentinel-1 CSAR IW acquired on 24 September 2018 at 21:31:00 UTC
Author(s): Sentinel Vision team, VisioTerra, France - svp@visioterra.fr
Keyword(s): Coastal, archipelago, emergency, natural disaster, climate change, typhoon, rain, precipitation, mine, Philippines
Fig. 1 - S3 SLSTR (12.09.2018) - S2,S3,S1 - Mangkhut approaching Philippines, red S1 footprints encase Itogon & Naga cities.
Fig. 2 - S1 (04 & 16.09.2018) - vv,vh,vv colour composite - Mangkhut-caused precipitations flooded Luzon province.
Typhoon Mangkhut was highlighted in a previous Sentinel of the Day as it was approaching Philippines. Soon after, it was still a category-5 cyclone, which blew 240km/h winds as it passed over Philippines the 15.09.2018. It also caused heavy rainfalls which provoked flooding and landslides.
Fig. 3 - S2 (01.08.2018) - 4,3,2 natural colour - Itogon mining city in Luzon province.
Fig. 4 - S2 (20.09.2018) - 4,3,2 natural colour - Itogon after the lanslide that killed 80.
Fig. 5 - S1 (04.09.2018) - vv,vh,vv colour composite - Itogon before the landslide.
Fig. 6 - S1 (16.09.2018) - vv,vh,vv colour composite - Itogon after the landslide, the alluvial cone shows as a purple triangle
Fig. 7 - S2 (24.06.2018) - 4,3,2 natural colour - Naga city in Cebu Province before rainfalls triggered a landslide around its mine.
Fig. 8 - S1 (12.09.2018) - vv polarisation, σ0 processing, Naga city before the landslide.
Fig. 9 - S1 (24.09.2018) - vv polarisation, σ0 processing, Naga city after the landslide.
Landslide in Naga City, Cebu Philippines, September 2018. Source: Cebu Provincial Government
Fig. 10 - S1 - red (12.09.2018), green (24.09.2018), blue (12.09.2018), vv polarisation - Multi-temporal view of Naga landslide.
The differences between the images acquired the 12 and the 24 September show in green or magenta. This image highlights a massive landslide that happened within Naga mine on 20 September after a period of heavy rain. It killed 53 people while 50 others remain missing.

According to the Copernicus-endorsed floodlist.com: "The landslide occurred in or close to a cement quarry. The Philippines Department of Social Welfare and Development said that areas around the quarry have been evacuated, with at least 427 families displaced." It seems many came back home when the typhoon was announced further North. The wobbly house foundation didn't support the severe rain that poured in a short period of time.

As a consequence, "Cebu Governor, Hilario P. Davide III visited the area and ordered the temporary stoppage of all quarry operations in Cebu Province. The governor also requested a review into quarry permits issued by the Province to make sure that the areas of operation of these companies are implementing safety measures for the nearby residents."