Colima volcano (Mexico): July 2015 Montitlán pyroclastic flow deposit a year later
On 11 July 2015, a large dome collapse triggered the second largest block and ash pyroclastic flow of the 21st century (surpassed by Merapi in 2010 only), filling and devastating the Montitlán river valley on Colima's south side to a length of about 10 km.
We visited the deposit approx. 16 months later, in Nov 2016 (compare these to photos taken few days after it was deposited). This fresh, the deposit is a fantastic geologic showcase. It provides extremely interesting insights into the dynamics of this kind of pyroclastic density currents and its origin:
We visited the deposit approx. 16 months later, in Nov 2016 (compare these to photos taken few days after it was deposited). This fresh, the deposit is a fantastic geologic showcase. It provides extremely interesting insights into the dynamics of this kind of pyroclastic density currents and its origin:
 The pyroclastic flow deposit at the exit of the Montitlán ravine; its surface is still barren, but s... [info] (175 Hits) |  Large, partially burnt or charred tree trunks abound in the deposit, witness of the destructive powe... [info] (166 Hits) |
 View towards the volcano in the background, mostly hidden beneath its afternoon cloud (Photo: Tom Pf... [info] (139 Hits) |  View upstream of the flow deposit; Livio gives a scale. (Photo: Tom Pfeiffer) [info] (140 Hits) |
 A smaller part of the flow traveled through a parallel side valley. (Photo: Tom Pfeiffer) [info] (126 Hits) |  After reaching the exit of the narrow gorge, the flow widened, surpassed the banks of the valley and... [info] (118 Hits) |  During transportation within the turbulent block and ash flow, the blocks constantly bounce against ... [info] (111 Hits) |
 New life often starts at the dead wood pieces. (Photo: Tom Pfeiffer) [info] (115 Hits) |
 Heike, Ingrid and Livio examine the rocks left by the flow. (Photo: Tom Pfeiffer) [info] (107 Hits) |  Some of the blocks are several meters accross,- once pieces of the lava dome on top of the volcano. ... [info] (94 Hits) |  First plants manage to grow on the deposit after more than a year. (Photo: Tom Pfeiffer) [info] (89 Hits) |  Close-up of a rock sample: a block of juvenile magma (from the dome or lava flow) made of blackish, ... [info] (93 Hits) |
 As we visit the deposit, smaller rockfalls occur on the active lava flow from the volcano behind; th... [info] (93 Hits) |
 In the lower part of the deposit, where the flow was about to loose its energy, parts of the old gro... [info] (85 Hits) |  Rainfalls, in particular heavy ones, have started to re-excavate the river valley in more or less th... [info] (90 Hits) |  The latest erosion allows to study fresh cross-sections of the pyroclastic flow deposit. (Photo: Tom... [info] (90 Hits) |
 Livio standing on top of the deposit viewed from the new river channel. (Photo: Tom Pfeiffer) [info] (85 Hits) |  View of the fine-grained base layer of the block and ash flow (upper portion of section). (Photo: To... [info] (79 Hits) |
 The deposit is a chaotic mixture of fine gray ash with blocks and burned wood pieces. (Photo: Tom Pf... [info] (85 Hits) |  The furthest tongue of the flow, at approx. 10 km distance from its source. (Photo: Tom Pfeiffer) [info] (82 Hits) |
 A large pine tree fell victim as it stood at the very edge of the flow. (Photo: Tom Pfeiffer) [info] (90 Hits) |  Despite the intense heat of the ash at the moment it arrived (several hundred C), the tree didn't bu... [info] (76 Hits) |  Dried-out pine cones still hang in on the dead branches. (Photo: Tom Pfeiffer) [info] (74 Hits) |
 The death of the tree became source of life in turn: its needles and hundreds of pine cones fell on ... [info] (78 Hits) |
