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Prehistoric Human Response to Climate Change 2010

OK I have another question, Claude - I notice you are very close to the coast but your archaeological sites look like they are on a bluff or hill that's a few tens of feet higher than sea level. How was sea level different when these sites were occupied? Were the sites lower and closer to the water? yours, Mike

Sun, 07/25/2010 - 16:39

Michael Wing

OK now I'm very curious about your mention of tsunamis. How has sea level changed, and how frequent are tsunamis in your area? What a DYNAMIC location you inhabit! yours always, Michael Wing

Tue, 07/27/2010 - 00:19

Claude Larson

Hi Michael,Well, we are right at the edge of the Bering Sea and we are in the Ring
of Fire where volcanoes erupt and earthquakes are frequent, so putting
all of that together tsunamis seem to be in order here. I actually
spent the day with SeanPaul yesterday digging holes and measuring layers
of soil, sand and tephra. Sometimes layers appear between the tephra
that don't appear on the high terraces. They sample those layers and
make notes about them. If the grains of the layers are angular it is
most likely that the deposit is from the river during a storm or flood.
But, if the layers are more rounded particles they are likely to have
come from the sea and became rounded by ocean tumbling. Those rounded
particles can be indicators of tsunamis. They collect the samples and
are taking them back to analyze them to make determinations. Then they
look at their notes and strata drawings and can give approximate dates
of tsunamis based on what they know about the volcanic eruption dates.
It's pretty incredible really - all this from playing in the sand box.
Claude

Sat, 07/31/2010 - 22:18

Claude Larson

Hi Michael,You are very observant. Our archeological sites are up on high terraces that are about 40 meters above sea level (about 120 feet). The sea was covering the terrace our base camp is located on and the high terraces were at the edge of the sea thousands of years ago. So the sites weren't lower, the ocean was higher is what I think the answer to your question is.
blue skies,
Claude