Smart Rock

Podcast

Smart Rock

Transcript

A different kind of rolling stone. I'm Bob Hirshon and this is Science Update.

During a flood, most people are only concerned with how high the water will rise. But some scientists are also interested in what happens to the dirt and soil under the water.

That's why geographer David Sear, at the University of Southampton in England, is part of a team developing an intelligent pebble that records its own movements during a flood.

Sear: It will log signals from a grid of wires laid out on a beach, the idea being that we will be able to determine from the signals that the pebble logs, where it is at any point in time, during either a river in flood, or along a beach during a tide.

The device is shaped and weighted much like the pebbles around it. So it'll follow the same path and take the same tumbles. Dr. Sear says the information it records may be useful to soil conservation efforts.

Sear: The movement of sediment relates to erosion and deposition. And that relates, again, to loss of farmland, loss of physical habitat, loss of coastline, and damage to infrastructure.

And these high tech pebbles can help researchers better predict these changes.

For the American Association for the Advancement of Science, I'm Bob Hirshon.

Making Sense of the Research

Sediment transport processes are natural, but over time can lead to coastal erosion or river flooding. Therefore, scientists are interested in learning more about where the sediment comes from, where it goes, and how human activities (e.g., removing trees and grasses) are affecting this process. As you just learned, according to Dr. David Sear, there are economic benefits to understanding and predicting sediment transport. "Along coasts the removal of sediment can erode beaches, while in rivers the deposition of sediment can result in loss of channel capacity, leading to flooding. The country spends millions each year on maintaining river flows and on sea defenses." The ability to predict erosion patterns will help communities to better evaluate future development plans, among other things.

To find out exactly what happens to sediment on it's waterborne journey, Dr. Sear and his colleagues have developed an "intelligent pebble." Made from resin, the "pebble" contains a battery and microchip, which send signals that can be tracked and logged. A precise history of the pebble's movements can be collected and downloaded, giving researchers a clearer picture of the process of sediment transfer. This information can help researchers to develop better models for predicting how erosion and deposition will change coastline and river systems in the years to come.

Now try to answer the following questions:

1. What is the purpose of the "intelligent pebble?"
2. What kind of information will the pebble allow researchers to collect?
3. What other methods do researchers have for collecting information about erosion and sediment transport? What is unique about the information that can be gathered from the pebble?
4. Why are researchers concerned about understanding sediment transport? What will this research inform?
5. Imagine this technology could be easily adapted for other purposes. How might you use this technology? What movement would you track? Why? What would this collected data inform?

Going Further

For a summary of a comprehensive study of erosion impacts conducted in 2000 by the Federal Emergency Management Agency (FEMA) and the Heinz Center for Science, Economics and the Environment, read the PDF document (with images) titled Evaluation of Erosion Hazards Report Brief .

To learn more about the impact of coastal erosion on beachfront communities, read CNNfyi.com's Beaches on the Brink and FEMA's Significant Losses From Coastal Erosion Anticipated Along U.S. Coastlines.

For an introductory lesson on erosion processes for grades 3-4, try Water & Soil Erosion from the Educational Resources Information Center (ERIC) database.