Rosas in Cauca, Columbia: a truly extraordinary landslide

This is a truly extraordinary period for landslides, with so many events occurring that it is hard to decide which to cover.  In India, the Joshimath landslide is continuing (rightly) to gain a lot of attention as the situation continues to deteriorate.  Demolitions are underway, but are being fiercely opposed by local residents.  There remains a complete lack of clarity as to the technical situation, which will be causing considerable distress.  This is a abject lesson in poor communication by the authorities.

It is reported that the number of affected properties has now reached 723.  Unfortunately there is some rainfall in the area, which could exacerbate the situation.

Meanwhile, California is being struck by a series of atmospheric river events, with serious impacts  There are some amazing landslide videos on Twitter.

Meanwhile, in Colombia a truly remarkable landslide has occurred in Rosas, Cauca.  There are some excellent Tweets providing detail, including this one containing drone footage of the slide:-

Sobrevuelo con dron deja ver la gran magnitud del deslizamiento de tierra con aproximadamente 850 m de ancho y 900 m de largo que afectó 3 veredas del municipio de Rosas, Cauca 🇨🇴

📹 créditos en el video.
pic.twitter.com/5wRuSNfGHJ

— Geotweets (@Yobanygf) January 11, 2023

.

This landslide, which started to develop on 6 January 2023 but fully failed on 9 January 2023, has destroyed the communities of Parraga Viejo, Santa Clara, La Soledad and Chontaduro.  It is reported that 64 homes have been destroyed, rendering 164 families and over 700 people homeless.  The landslide has also closed over 500 metres of the Pan American Highway between Popayán and Pasto.

The best image I have found is this one, which was tweeted by Christian Mejia:-

The 9 January 2023 landslide at Rosas at Cauca in Columbia. Image tweeted by Christian Mejia.

.

The location of the landslide is described in a tweet by Willian Burbano:-

https://twitter.com/wilbuz/status/1612628816014237696

.

The coordinates of the Rosas landslide are 2.249, -76.779.  The ever reliable Helbert Schneider has tweeted some background information about the landslide:

The material involved is highly weathered Pliocene tuffs of the Galeón Fm. In this area, a soil avalanche killed 33 people on April 21, 2019.

— Helbert García-Delgado (@HelbertSchneid1) January 10, 2023

.

Plans are underway to purchase the land from the affected families, allowing them to relocate, whilst humanitarian assistance is being provided as an interim measure.