The Beauty of Dust

"E-mail Melanie Martella

One of the many, many, many things I love about the Internet is the sheer variety of astounding pieces of information it makes available. For instance, what do the Amazon, a bunch of dead Londoners from 1258, and a beach all have in common? Dust, as it happens. Different types of dust, I grant you, but dust all the same.

Let's take the Amazon first, shall we? Alexis Madrigal's article "Today in Astonishment: The Amazon Rainforest Gets Half Its Nutrients From a Single, Tiny Spot in the Sahara" in The Atlantic presented the startling fact that a great whack of the necessary nutrients required to make the Amazon the lush and ecologically varied place that it is are supplied by dust originating in a single, small patch of the Sahara. The full text of the 2006 paper in Environmental Research Letters is online and you can read it here. I'd advise you to do so because it's a really interesting read with gorgeous and informative graphics. In this case, analysis of satellite images allowed the researchers to track and quantify the seasonal flow of dust from its source in the Bodélé depression.

In 1990, a group of archeologists excavating in London found several mass graves, dating from the 13th century. Considering all the things that could, and did kill large quantities of the populace during that time frame (warfare, famine, and epidemic disease to name three of the biggies) the historians figured that either the Great Famine or Black Death had caused all the bodies. Not so! As the Museum of London Archeology (MOLA) reports, the culprit has now been pegged as a massive volcanic eruption somewhere in the tropics that threw such large quantities of sulfurous gases and fine particulates into the air that it blocked sunshine, blighting the crops, wrecking the weather, and killing tens of thousands of people. When you think of the havoc caused by the 2010 Icelandic volcano and its comparatively tiny ash plume, it's no wonder that the University of Wisconsin's Space Science and Engineering Center maintains a Volcano Watch site to provide up-to-date satellite imagery of the world's most active volcanoes.

Flowing water is a powerful thing (e.g., the many different courses taken by the Mississippi river over the years), and because people tend to live and farm near bodies of water, coastal and river erosion is a very big deal. Monitoring erosion is important; increased sediment clogs navigable channels while flowing water can eat away at beaches, coastlines, and riverbanks. Researchers at the University of Georgia's Center for Geospatial Research have used LiDAR and satellite images as well as historical maps of Jekyll Island to figure out how its coast will fare when faced with storm surges and rising water levels. Meanwhile, the USGS is using drones to gather erosion data on, among other things, Missouri River erosion in South Dakota.

Dust. Who knew?