Rio Rayas Bridge
Rio Rayas bridge is located 2.5 kilometers (1.5 miles) north-northeast of
Chaitén’s caldera rim, in an area that was peppered with gravel-sized
tephra on May 6, 2008. The gravel that fell into the forest stripped leaves
and small twigs from the canopy and incorporated this organic material into
deposits that accumulated on the ground, up to 25 cm (9.8 inches) thick in
some places. In the process, tree canopies were severely damaged, having
initially lost in excess of 90 percent of their crown, but some species have
since sprouted new foliage along their trunks and major limbs, some in as
few as 4 months after the eruption. Understory vegetation also was severely
affected, but some species, like nalca and bamboo, sprouted from root systems
in the pre-eruption soil within the first year.
The river crossed by the
bridge, Rio Rayas, flows along the east flank of Chaitén in an area
of very thick deposits of sand and gravel tephra from the eruption. Flooding
that began shortly after the eruption deposited
1 to 2 meters (3 to 6 feet) of material onto areas along the Rio Rayas. Deposits
of a meter ( 3 feet) or more thick killed forests growing in the floodplain.
Click photos to enlarge.