Stalagmites May Predict Next Big One Along The New Madrid Seismic Zone

Small white stalagmites.
Insert: one stalagmite cut vertically in half, showing
generations of growth with the white one on top.
Credit: Courtesy of K. Hackley

Small white stalagmites lining caves in the Midwest may help scientists chronicle the history of the New Madrid Seismic Zone (NMSZ) – and even predict when the next big earthquake may strike, say researchers at the Illinois State Geological Survey and the University of Illinois at Urbana-Champaign.

While the 1811-12, magnitude 8 New Madrid earthquake altered the course of the Mississippi River and rung church bells in major cities along the East Coast, records of the seismic zone’s previous movements are scarce. Thick layers of sediment have buried the trace of the NMSZ and scientists must search for rare sand blows and liquefaction features, small mounds of liquefied sand that squirt to the surface through fractures during earthquakes, to record past events. That’s where the stalagmites come in.

The sand blows are few and far between, said Keith Hackley, an isotope geochemist with the Illinois State Geological Survey. In contrast, caves throughout the region are lined with abundant stalagmites, which could provide a better record of past quakes. “We’re trying to see if the initiation of these stalagmites might be fault-induced, recording very large earthquakes that have occurred along the NMSZ,” he said.

Hackley and co-workers used U-Th dating techniques to determine the age of stalagmites from Illinois Caverns and Fogelpole Cave in southwestern Illinois. They discovered that some of the young stalagmites began to form at the time of the 1811-12 earthquake.

The Descent Adopt-a-Cave Scheme

In 1977 Descent began a scheme to recognise and encourage the work of clubs and individuals in helping to preserve our underground environment. Today the Descent Adopt-a-Cave Scheme is more important than ever – without cavers maintaining our caves, our subterranean heritage would truly suffer. Joining the scheme does not confer any rights, it doesn’t help with access, but it does show that you care.

To participate, drop a line to Descent – and, of course, let us know if your club is unable to continue its involvement. In the Peak District, Conservation Officer Dave Webb acts as our agent to encourage cavers to join in and is happy to talk to people about their participation.

http://www.wildplaces.co.uk/adoptacave.html

Caves offer variety of challenge

Caver Mike Wiles is sh0wn at Jewel Cave National Monument,
S.D., in October of last year. He and other volunteers
helped map the cave past 142 miles, making it the second
longest cave in the world.

Perceptions aside, caving can be safer than many other activities

Caver Mike Wiles has helped document the far reaches of this cave that's a favorite Black Hills tourist attraction, but tours are available here year-round and elsewhere for the more casual explorer.

Wiles and other volunteers mapped Jewel Cave's passageways past 142 miles, making it the second-longest cave in the world. Nearby Wind Cave National Park is the eighth longest.

Some people have made caving out to be an extreme adventure, but it's really safer than a lot of activities on the surface, he said. The challenge and thrill come from discovering corridors that have never been reached — sometimes after days underground.

"I don't go for the rush. But instead of a rush I just have this long-term, continuous enjoyment with it. That way I don't get burned out," Wiles said.

68-year-old man from Styria tried to kill cave explorers

Hate and anger about cave explorers was the motivation for an attempted murder by a 68-year old man from the North Styrian town of Liezen.

The 68-year-old environmentalist wanted to protect “his mountain” from explorers and adventurers, he told the police after his detention.

He put up a stone trap on a sea level of 2.600 metres, close to the certain cave. The stones were stacked up and connected with a rope. If someone would use the rope, he would be killed by the fallen stones.

It was not the first time that the angry 68-year-old man displayed behavioural problems in this case. He also made telephon terror against police and the potholers, and there is also a suspicion that he has scratched two cars of the cave explorers.

At the moment the suspect is sitting in the prison of Leoben. The evidence is overwhelming.

Source: Austrianews