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GEOPHENOMENA

Earthquake hits Peru
Fires in Florida
Three Sisters uplift in Oregon
Cooler days on the farm
Warplanes attack ice

Earthquake hits Peru
June 25, 2001
A magnitude-8.1 earthquake at 33 kilometers deep shook Peru on Saturday, June 23,  says the USGSs National Earthquake Information Center, upping previous estimates that put the quake's magnitude at 7.9. The focus was just off the Peruvian coast, about 120 miles west of Arequipa, Peru's second largest city. Three major aftershocks followed ranging from magnitude 5.5 to 6.3.

 Debris and collapsed homes killed at least 70 people, most in Arequipa, and over 30 people are missing from Camana, a nearby coastal town deluged by a quake-induced tsunami. A landslide blocked the main road into Moquegua, 60 miles from Arequipa, keeping emergency food and medicine from a town where 17 people were killed and 80 percent of the houses seriously damaged or flattened.

Stretched out against an active continental margin, Peru is no stranger to big quakes. The most memorable was the devastating magnitude-7.7 event in 1970 that killed approximately 70,000 people during an avalanche of rock and snow on Mount Huascarán, a little over 200 miles north of Lima.

For more information please see:
earthquake.usgs.gov/activity/latest/eq_01_06_23/index.html
EJ
 

Fires in Florida
So far this year almost 2,700 wildfires have attacked Florida, burning approximately 204,000 acres, the Associated Press reported May 25. That month, 15 large blazes dotted the peninsula, from Pensacola down to Collier County and into southwest Florida.

By May 20, a week-old fire in the Big Cypress National Preserve, about 75 miles west of Miami beyond Everglades National Park, had burned 22,500 acres and was only 25 percent contained. Another 3,000-acre fire in the region was 95 percent contained.

Firefighters working on the Mallory Swamp fire in southeastern Lafayette County are getting aid from the federal government. Despite firefighters’ efforts that managed to contain the blaze by 25 percent on May 24, the difficult fire had destroyed 20,000 acres as it grew in different directions.

In the Fakahatchee Strand, a state preserve in Collier County, underbrush in swampy, rugged terrain helped fuel a 12,800-acre fire to reach Picayune State Forest. Firefighters had mostly contained a 300-acre fire in another swamp in the Panhandle, north of Panama City. A lightning strike started a 950-acre fire near Haines City in Polk County, forcing 30 homes to be evacuated.

At least 75 firefighters were working on a 1,400-acre fire near Walt Disney World. The Disney fire sent smoke into the resort area 3 miles away and into Orlando, about 30 miles northeast. All area theme parks remained open as of late May.
CR
 

Three Sisters uplift in Oregon
On May 8, U.S. Geological Survey scientists reported a slight swelling, or uplift, of the ground surface over a broad area centered 5 kilometers (3 miles) west of South Sister volcano in the Three Sisters region of the central Oregon Cascade Range. The Three Sisters region is located 35 kilometers (22 miles) west of Bend, Ore., and 100 kilometers (60 miles) east of Eugene, Ore. The radar interferogram at right shows the pattern of ground uplift. Each full color band from blue to red represents about 2.8 centimeters of ground movement in the direction of the radar satellite. In this case, four concentric color bands show that the surface moved toward the satellite (mostly upward) by as much as 10 centimeters (about 4 inches) sometime between August 1996 and October 2000.

No information is available for uncolored areas, where forest vegetation or other factors hinder acquisition of useful radar data. A numerical model places the source of the uplift about 7 kilometers (4 miles) beneath the ground surface. The most likely cause is magma accumulation in the crust, a process that has been observed with radar interferometry at several other volcanoes. At Three Sisters, there is no immediate danger of a volcanic eruption or other hazard. The U.S. Geological Survey, in cooperation with the U.S. Forest Service, is analyzing additional information and installing new monitoring instruments to determine if the uplift is continuing.
CR
 

Cooler days on the farm
In 1880, about 50 percent of the land in both the Midwest and northeastern United States was cultivated cropland.  Since then, the Midwest has undergone increased deforestation and farming while the East has seen reforestation. Because crops reflect more sunlight back into space than forests do, this major conversion of forest to cropland has led to a detectable cooling of the Midwestern climate, according to Gordon Bonan of the National Center for Atmospheric Research (NCAR). He published work in the June issue of the Journal of Climate.

Before conducting his latest research, Bonan had designed a model that predicted this regional cooling, in contrast to other regional climate studies forecasting cooler temperatures in the northeast due to regulation by clouds. To make empirical observations, Bonan used 10 years of data from 65 U.S. weather reporting stations isolated from the influence of cities or water bodies. He compared daily temperature ranges in the predominantly forested areas of the Northeast and in the cultivated lands in the Midwest. In his recent research, Bonan reported that daytime temperatures rose more in the Northeast than in the Midwest, supporting his prediction. He also analyzed a 100-year record of U.S. temperatures to minimize inaccuracy from small data sets. Bonan continues to use a computer model to further investigate the influence of historical deforestation on the eastern United States.
EJ

Warplanes attack ice
Between May 18 and 22, Sukhoi-24 (SU-24) bombers blasted apart a huge ice floe that had blocked meltwater from moving down Siberia's Lena River to the Arctic, Reuters reported. The trapped meltwater flooded the Siberian town of Lensk, where many of the 30,000 residents were rescued from their rooftops by helicopter. The bombing released a meter-high wave of water into the already swollen river that then threatened to inundate the city of Yakutsk, the capital of Russia's largest diamond-mining republic, Sakha-Yakutiya.

In Yakutsk, which is about 35 miles downstream of the ice dam, buses mounted with loudspeakers warned residents of the possible use of an air-raid siren to indicate the need for evacuation.

Authorities also banned the sale of vodka and other strong alcohol, explaining: "If the water hits the city, it will be very cold and people will start warming themselves up the usual Russian way," a spokeswoman for the Yakutsk administration told Reuters. "It will be much easier for us to save them if they are sober."

Although turned to chunks, the ice floe still did not budge after the warplanes dropped 72 bombs. It took the work of helicopter gunships to shift the ice to the point of allowing the meltwater wave to pass.
CR



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