Pacific Northwest Research Station

Chaitén Photoessay

Rio Amarillo Bridge

The Rio Amarillo bridge (pictured in the first two photos) is located at the small developed area of Amarillo, about 20 kilometers (12 miles) southeast of Chaitén Volcano. The Rio Amarillo watershed experienced up to about 20 cm (9 inches) of tephra fall, but at this location, tephra fall was less than 10 cm (4 inches), so the surrounding landscape does not show much change besides an increase in sediment flow. The river flows from a glacier on the south flank of Michimahuida volcano, which borders Chaitén, and transported high loads of Chaitén tephra washed from hillslopes by the first rains after the eruption. Now, however, evidence of high sediment loads is not as evident as it is along other rivers closer to the volcano, where deposits smothered forests.

The three additional photos show a former wetland area along a tributary of the Rio Amarillo where the stream deposited remobilized tephra in the flooding shortly after the eruption began, but has been removing them since that time. The 1-3 meter thick (3-10 feet) deposits killed the riparian forest during the first post-eruption year. However, by the third post-eruption year, the stream had cut new channels into these deposits, setting the stage for growth response of vegetation.

Photo Gallery

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