Anchors Away!

Hi friends,

We're just finishing up drilling operations at our first site and should be setting course for our next site up the Australian coast later today. While the ship has a dynamic positioning system that keeps our position remarkably stable while we're on site (see this Wikipedia article for more on that), we'll soon have to turn it off for our transit, so the ship is about to start rockin' again. It should take us about 12 hours to reach the new site.

Our drilling at this first site (now known as IODP Site U1482) was quite successful in terms of providing sediments useful for research on the history of the Western Pacific Warm Pool. Tiny protists called foraminifera (or "forams") have been found throughout the samples the paleontologists have looked at so far, so we're all pretty excited. Forams can be found in all but the coldest parts of the world's oceans and often secrete a "test", or shell, made of calcium carbonate from carbonate and calcium ions in seawater. Calcium carbonate is the same chemical compound you would as the main component in find in limestone, marble countertops, or even cement. Most of the species documented thus far live in sediment on the surface of the seafloor, but a few also live within the water column at different depths. Just make sure you bring your microscope if you want to look for them - most forams are < 1 mm in diameter, so your chances of spotting one with your naked eye are pretty slim.

Why is a ship full of scientists so excited about a bunch of tiny forams? Well, it turns out that many of our most fruitful methods for learning about changes in climate and ocean circulation that happened millions of years ago involve measuring the concentrations of elements present as minor or trace components within calcium carbonate. These elements include magnesium (Mg), strontium (Sr), barium (Ba), boron (B), and cadmium (Cd). While calcium and carbonate form the dominant components of a foram's test, small amounts of each of these elements (as ions dissolved in seawater) will substitute for either calcium or carbonate as the test is formed. Past research has shown that the amount of each of these elements that substitutes into the foram test depends on variables such as water temperature, salinity, the element's concentration in seawater, or - more commonly - some combination of these variables. Thus, measuring the concentrations of these components within foram tests can give yield valuable information about how these variables have changed through time (and how they might change in the future with anthropogenic climate change). This is what many of the scientists on this expedition plan to do with the samples collected once we're back on shore. I'll actually be doing something completely different by looking at the chemistry of water samples collected during the expedition, but more on that to come.

That's all for now, but until next time - Go, Cubs, Go!

- Dan