{"id":40987,"date":"2022-05-20T07:01:32","date_gmt":"2022-05-20T07:01:32","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=40987"},"modified":"2022-05-20T07:01:32","modified_gmt":"2022-05-20T07:01:32","slug":"mount-popa-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2022\/05\/20\/mount-popa-1\/","title":{"rendered":"The Mount Popa debris avalanche"},"content":{"rendered":"

The Mount Popa debris avalanche<\/h4>\n

Yesterday, in response to the coverage of the 42nd anniversary of the 1980 Mount St Helens flank collapse and eruption<\/a>, Wang Yu (@Wangyu1979<\/a>) tweeted a Google Earth image of the Mount Popa volcano in Myanmar<\/a>.\u00a0 This is my version of the image that he tweeted:-<\/p>\n

\"Google

Google Earth image of the aftermath of the flank collapse at Mount Popa in Myanmar.<\/em><\/p><\/div>\n

.<\/p>\n

The image beautifully illustrates that Mount Popa has also undergone a flank collapse event (a flank collapse is an extremely large-scale landslide on the flanks of a volcano<\/a>).\u00a0 The huge gap in the side of the volcano is the scar of the landslide.<\/p>\n

The sequence of events at Mount Popa is described in a paper published in 2018 in the The Journal of Volcanology and Geothermal Research<\/em><\/a> (Belousov et al.<\/em> 2018<\/a>).\u00a0 They demonstrated that Mount Popa underwent a catastrophic flank collapse about 8,000 years ago.\u00a0 The resultant debris avalanche, which had a volume of about 1.3 cubic kilometres, travelled about 11 km from the former summit of Mount Popa.\u00a0 The landslide debris is 5.5 km wide and on average 50 m thick.<\/p>\n

By any standard this is a vast landslide.<\/p>\n

On the Google Earth image below I have marked the approximate boundaries of the debris avalanche deposit – it is reasonably easy to see in the landscape at this scale:-<\/p>\n

\"Google

Google Earth image of the aftermath of the flank collapse at Mount Popa in Myanmar, marked with the approximate boundaries of the debris avalanche.<\/em><\/p><\/div>\n

.<\/p>\n

Belousov et al.<\/em> (2018<\/a>) suggest that prior to the collapse, magma moved up through the volcano, whereupon the flank collapsed.\u00a0 Unlike Mount St Helens, there is no evidence of a directed blast.\u00a0 The landslide occurred in two stages, with an initial failure of about 1 cubic kilometre, followed by a smaller (0.3 cubic kilometre) secondary failure shortly after.\u00a0 The subsequent volcanic eruption generated pyroclastic flows that are now draped over the landslide deposit.<\/p>\n

There is no geological evidence of any volcanic eruption since this date, although some historical accounts suggest that some sort of small event occurred in the year 442 BCE.\u00a0 What this represents is uncertain in the absence of any geological evidence.<\/p>\n

There is no doubt that this site deserves more detailed investigation, but the scale of the geologically recent flank collapse at Mount Popa is truly epic.\u00a0 These huge volcanic landslides are some of the most impressive landslides on Earth.<\/p>\n

.<\/p>\n

Reference<\/h4>\n

Belousov, A., Belousova, M., Khin Zaw, Streck, M.J., Bindeman, I., Meffre, S. and Vasconcelos, P. 2018.\u00a0 Holocene eruptions of Mt. Popa, Myanmar: Volcanological evidence of the ongoing subduction of Indian Plate along Arakan Trench.<\/a> Journal of Volcanology and Geothermal Research<\/em><\/a>, 360<\/strong>, 126-138.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

About 8,000 years ago a massive landslide occurred on the flank of Mount Popa in Myanmar. The landslide, which had a volume of about 1.3 cubic kilometres, travelled about 11 km from the crater of the volcano.<\/p>\n","protected":false},"author":22,"featured_media":40994,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[544],"tags":[469,346,301,788,314,107],"class_list":["post-40987","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-review-of-a-paper","tag-featured","tag-flank-collapse","tag-myanmar","tag-review-of-a-paper-2","tag-se-asia","tag-volcano"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/40987","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/comments?post=40987"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/40987\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/40994"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=40987"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=40987"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=40987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}