Tuesday, February 28, 2012

Ocean Sciences Day 4: River Flux

Day 4 was cool. It was the last day of the conference, and the conference was capped by a special session devoted to Jon Milliman. Jon is one of the godfathers of this special sub-discipline of geomorphology and coastal oceanography focusing on the flux of sediment from land to the continental shelf and deep ocean. It was great to finally meet him and the community of researchers that has formed around him.

While many of the presentations were focused on the world's big and/or particularly productive rivers, they did let a presentation in that focused on the Umpqua, in Oregon. Bob Wheatcroft's presentation was unique amongst the group and, from my standpoint, the most enjoyable because of its relevance to the Elwha. The Umpqua is a relatively small, relatively unproductive (from a sediment standpoint) river that drains the coastal range. Bob was able to show how sedimentation patterns on the shelf in Oregon have changed over the last half century or so, mostly in response to logging. Specifically, they've documented a 2x to 4x increase in shelf sedimentation on the Oregon shelf starting after WWII. There are all sorts of interesting ramifications, particularly ecological. How do benthic organisms adapt to that? Is it a driver of ecological change on the continental shelf? I also wonder if there is a similar observable pattern on, in particular, west end rivers?

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