Ground penetrating radar being used to detect potential sinkholes and subsurface voids

from: http://www.geoprac.net/

When sewer pipes crack and leak, the surrounding ground becomes saturated and soil can migrate into the pipe and leave behind a void. Eventually this void can expand until it undermines the pavement or other structures forming a sinkhole. The same ground penetrating radar technology being used by geophysicists to perform subsurface characterization and by the military to detect roadside bombs in being adapted to detect these voids before they reach the surface. Researchers at Louisiana Tech University are developing a robot to traverse sewer pipes and scan around the pipe for potential voids using the GPR. The research is being performed with $3M from NIST and $3.2M from Cues, Inc. a Louisiana sewer inspection company. Additional trials are slated to take place this month.

A Cadillac Escalade sits at the bottom of a sinkhole at North and Oakland avenues in Milwaukee on July 24, 2010, after heavy rains caused the pavement to give way. New technology is being tested that can find empty spaces where dirt has seeped into sewers and water pipes before they spread to create huge potholes or sinkholes big enough to swallow a Cadillac. (AP File Photo/Mark Was)

http://www.geoprac.net/geonews-mainmenu-63/61-available-resources/1103-ground-penetrating-radar-being-used-to-detect-potential-sinkholes-around-sewer-pipes?utm_source=GeoPrac+030+-+January+2012&utm_campaign=Newsletter030&utm_medium=email

http://www.nola.com/traffic/index.ssf/2012/01/radar_used_in_stealth_bombers.html

http://dailyreporter.com/2012/01/03/radar-finds-potential-potholes-sinkholes-early/comment-page-1/

World's Largest Landslide - Saidmareh, Iran

Largest Landslide in the World

The Saidmareh Landslide in Iran moved about five cubic miles of material

http://geology.com/records/largest-landslide.shtml

 

Landsat image of Saidmareh landslide in Saidmareh, Iran. Image composed using data from NASA's GeoCover database. The source area is bounded on the southwest by the crest of the Kabir Kuh anticline. Debris from the slide travelled down the flank of the anticline, across the Karkheh River and continued across the valley floor. Some material in the slide was carried a distance of 14 kilometers (9 miles).

 The largest landslide that has been identified on Earth's surface is the Saidmareh Landslide located in western Iran. The slide occurred about 10,000 years ago when about 20 cubic kilometers (about 5 cubic miles) of Lower Miocene and Eocene limestone detached along bedding planes and slipped down the north flank of the Kabir Kuh anticline. The maximum vertical descent was about 1600 meters (5250 feet).

The sliding slab was about 15 kilometers (9 miles) wide and had a surface area of about 165 kilometers (64 square miles). Debris from the slide crossed the Karkheh River at the base of the slope and spread across the valley floor. Some material in the slide had a travel distance of over 14 kilometers (9 miles).

The slide debris dammed the Karkheh River, causing a large lake to form behind the dam. The lake persisted long enough for up to 150 meters of sediment to accumulate on its bottom (these sediments currently support several thousand acres of cultivated land). The lake then breached the dam and eroded a channel through it.

For more information on the Saidmareh Landslide:

[1] Shoaei, Z. and Ghayoumian, J., 1998, Seimareh landslide, the largest complex slide in the world, In: Moore D. and Hungr O. (editors), Eighth International Congress of the International Association for Engineering Geology and the Environment, Proceedings, Pages 1337-1342.

[2] Harrison, J.V. and Falcon, N.L., 1937, The Saidmarreh Landslip, Southwest Iran, Journal of Geology, Volume 84, pages 42-47.

[3] Petley, D., 2009, The biggest landslide of them all - Saidmareh, Iran, Dave's Landslide Blog.