{"id":25714,"date":"2017-09-21T22:27:55","date_gmt":"2017-09-21T22:27:55","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=25714"},"modified":"2017-09-21T22:27:55","modified_gmt":"2017-09-21T22:27:55","slug":"valley-blocking-slips","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2017\/09\/21\/valley-blocking-slips\/","title":{"rendered":"Landslides from the Kaikoura earthquake part 5 – other valley-blocking slips"},"content":{"rendered":"

Landslides from the Kaikoura earthquake part 5 – other valley-blocking slips<\/h4>\n

In addition to the large valley-blocking slips that I featured in my earlier posts in this series<\/a>, the Kaikoura Earthquake<\/a> triggered many other valley-blocking landslides<\/a>.\u00a0 Most of these were of a medium size, and breached soon after the earthquake without causing any major issues.\u00a0 This is a very spectacular example:-<\/p>\n

\"valley-blocking

A valley-blocking slip from the Kaikoura earthquake.<\/p><\/div>\n

.<\/p>\n

This is quite a spectacular example of a rockslide on a planar surface that has destroyed a ridge.\u00a0 It clearly impeded the channel on the right of the image, and blocked the main drainage line.\u00a0 A small lake is visible.\u00a0 However, from above the head scarp it is clear that the landslide dam is not causing major issues:-<\/p>\n

\"valley-blocking

An alternative view of a large valley-blocking slip from the Kaikoura earthquake.<\/p><\/div>\n

.<\/p>\n

Further the south there are some reasonably large slumps that also blocked the valley:<\/p>\n

\"valley-blocking

A valley-blocking slip from the south of the area affected by the Kaikoura earthquake.<\/p><\/div>\n

.<\/p>\n

Again the lakes created by the blockages are very clear, but they are neither large nor particularly troubling.\u00a0 Of course the impact on the farmers who owned these areas of land is large though.<\/p>\n

In the higher areas there are some classic rockslides that have impeded the river.\u00a0 This very complex example had quite a large runout:<\/p>\n

\"valley-blocking

A reasonably-significant valley-blocking rockslide. Note the secondary failure above the main slide<\/p><\/div>\n

.<\/p>\n

This appears to be a planar rockslide.\u00a0 The additional slide on the ridgeline, in a weathered material, is an interesting juxtaposition with the main slide.\u00a0 Given the location of the deposit, it seems likely that this happened after the main rockslide.\u00a0 The remains of the lake are visible.\u00a0 In this case there was significant incision through the fine-grained dam at the point of the breach.<\/p>\n

Finally, some of the rockslides are actually quite simple:<\/p>\n

\"valley-blocking

A simple valley-blocking rockslide from the Kaikoura earthquake.<\/p><\/div>\n

.<\/p>\n

This landslide briefly blocked the Clarence River, but has now comprehensively breached.<\/p>\n

Landslides from the Kaikoura Earthquake<\/h4>\n

The earlier posts in this series are as follows:<\/p>\n