Working 5 to 9: Chemical Data From Forams Predict Sea Level Rise of Five to NINE Meters

      A friend from the Environmental Protection Agency (EPA) sent this article by Scott K. Johnson to several of us on his contact list. He wants to be sure the word gets out. The article, published 1/23/17, discusses past, present, and future sea level rise based on chemical data from rock cores from around the world. 

       Thus, in the spirit of rogue US National Park rangers, I am spreading the word. You can read more about and sign up for updates from the "Alternate National Park Service" here.

        Researchers at Oregon State University led by Dr. Jeremy Hoffman, collected 104 individual sea surface temperature records from 83 different sediment cores. Each record is based on a "chemical proxy" known to relate to water temperature, like the ratio of magnesium to calcium in the shells of foraminifera.

         A lot of the complicated work involved is precisely lining up each core record onto one timeline, synced to ice core records, and carefully calculating the uncertainties (much like lining up wood cores in dendrochronology).

       The article notes that our sea temperature is now about the same as it was 120,000 years ago during the last interglacial heat maximum. Based on the rock record, the oceans were then 6 to 9 meters (19.5 to 29.5 feet) higher than present time.   

     "If the planet stopped warming and stayed where it is today, the past gives us an idea of how much sea level rise we could expect to see in the long-term future. It would take much more than a century to complete that rise, but we are looking at well over five meters rise in elevation in the ocean." {This link lets you look at sea level rise at various levels around the world.}

     DT, are you sure you and your heirs want to keep staying in Manhattan when this happens? Could it be that glacial ice is giving you a hand signal that we all (including you) really need to attend to now?!

Keep rising up, scientists and writers! 
Steph

P.S. I just ordered a "RESIST" t-shirt for $11 from woot.com, designed by my friend's nephew. It's important to be a resistor now more than ever. . .

"Written" to the Core: A Core A Day

      Sediment coring from the bottom of the world's oceans includes miles of sediment and rock preserved at the USGS Repository here in Golden, CO, USA, as well as places like the Lamont-Doherty Core Repository.

     "Lamont has been actively collecting and archiving sediment from around the world . This is in large part due to Lamont's first director, Maurice Ewing, who instilled a philosophy of "A core a day" for all ocean research vessels. Ewing firmly believing that if we had the sediment we would be able to piece together patterns and stories about our planet, so every day at noon, or thereabouts, the ship would collect a core."

 The cores are used to reveal stories of earth systems, including those of climate cycles. Almost 40 years have passed since the groundbreaking work of the CLIMAP group that used the cores to connect the start of Earth's glacial cycles to changes in eccentricity, precession and tilt. (Hayes, Imbrie and Shackleton, 1976) . Collecting sediment on this Arctic GEOTRACES cruise will help scientists understand more of the stories locked in the oceans. 

    " The length of a core is dictated by the goal of the collection. Early Lamont cores were more about collecting just to gather the material because the ship was there. These early core were generally 6 to 9 meters long, although one incredibly long 28.2 meter core was collected from the Central Pacific. "

      For the sampling GEOTRACES is doing in the Arctic there is a specific goal of collecting just the top few dozen centimeters of sediment and the water just above it, yet at a depth of about 2200 meters. This will require a much different technique than what was used for the long Central Pacific core.

     "The sediment in this region is soft, so the plan was to drop a small general-purpose device called a Mono-corer over the side of the ship with a few small weights on top to help drive the core tube in straight."

     "The corer would hang below the bottom of the rosette of water samplers, far enough below that the rosette would remain 'mud-free' but still able to collect near bottom water samples. The mud in the mono-corer would be held in place by a spring-loaded door that snapped closed once the mud was inside and the tube began its return trip to the ship."

     You can read more about this technique, including the "Cone of Silence" here.

      I have two connections to these cores: a summer spent coring in the Mediterranean Sea on Duke University's Research Vessel Eastward and living in Lamont House (dorm) at Smith College, MA, USA.

       It was a fun summer.  What was your favorite educational summer?

Inspired to the core,
Steph