The emergency services said three Mexicans succumbed to the heat after illegally crossing the southern border. The border patrol and the Mexican consulate told AFP four migrants had died, however.

The high temperatures also killed about 25,000 cattle and 700,000 fowl in central California.

Temperatures have surpassed 40 C (104 F) in several parts of the state, and soared to a record 48 C (118 F) west of Los Angeles on Saturday.

Authorities say the state had not seen such high temperatures in 57 years. The temperatures fell back to their seasonal norm on Friday.

Conditions aren't much better a little farther north. Paul Smokov and his wife, Betty, raise several hundred cattle on their 1,750-acre ranch north of Steele, a town of about 760 people.

Fields of wheat, durum and barley in the Dakotas this dry summer will never end up as pasta, bread or beer. What is left of the stifled crops has been salvaged to feed livestock struggling on pastures where hot winds blow clouds of dirt from dried-out ponds.

Some ranchers have been forced to sell their entire herds, and others are either moving their cattle to greener pastures or buying more already-costly feed. Hundreds of acres of grasslands have been blackened by fires sparked by lightning or farm equipment.

"These 100-degree days for weeks steady have been burning everything up," said Steele Mayor Walter Johnson, who added that he'd prefer 2 feet of snow over this weather.

Farm ponds and other small bodies of water have dried out from the heat, leaving the residual alkali dust to be whipped up by the wind. The blowing, dirt-and-salt mixture is a phenomenon that hasn't been seen in south central North Dakota since the Dust Bowl of the 1930s, Johnson said.

North Dakota's all-time high temperature was set here in July 1936, at 121. Smokov, now 81, remembers that time and believes conditions this summer probably are worse.

"I could see this coming in May," Smokov said of the parched pastures and wilted crops. "That's the time the good Lord gives us our general rains. But we never got them this year."

Brad Rippey, a federal Agriculture Department meteorologist in Washington, said this year's drought is continuing one that started in the late 1990s. "The 1999 to 2006 drought ranks only behind the 1930s and the 1950s. It's the third-worst drought on record - period," Rippey said.

Svoboda was reluctant to say how bad the current drought might eventually be.

"We'll have to wait to see how it plays out - but it's definitely bad," he said. "And the drought seems to not be going anywhere soon."

Herman Schumacher, who owns Herreid Livestock Auction in north central South Dakota, said his company is handling more sales than ever because of the drought.

In May, June and July last year, his company sold 3,800 cattle. During the same months this year, more than 27,000 cattle have been sold, he said.

"I've been in the barn here for 25 years and I can't even compare this year to any other year," Schumacher said.

He said about 50 ranchers have run cows through his auction this year.

"Some of them just trimmed off their herds, but about a third of them were complete dispersions - they'll never be back," he said.

"This county is looking rough - these 100-degree days are just killing us," said Gwen Payne, a North Dakota State University extension agent in Kidder County, where Steele is located.

The Agriculture Department says North Dakota last year led the nation in production of 15 different commodity classes, including spring wheat, durum wheat, barley, oats, canola, pinto beans, dry edible peas, lentils, flaxseed, sunflower and honey.

North Dakota State University professor and researcher Larry Leistritz said it's too early to tell what effect this year's drought will have on commodity prices. Flour prices already have gone up and may rise more because of the effect of drought on wheat.

"There will be somewhat higher grain prices, no doubt about it," Leistritz said. "With livestock, the short-term effect may mean depressed meat prices, with a larger number of animals being sent to slaughter. But in the longer run it may prolong the period of relatively high meat prices."

Eventually, more than farmers could suffer.

"Agriculture is not only the biggest industry in the state, it's just about the only industry," Leistritz said. "Communities live or die with the fortunes of agriculture."

Susie White, who runs the Lone Steer motel and restaurant in Steele, along Interstate 94, said even out-of-state travelers notice the drought.

"Even I never paid attention to the crops around here. But I notice them now because they're not there," she said.

"We're all wondering how we're going to stay alive this winter if the farmers don't make any money this summer," she said.

"As difficult as this situation is, it could be a lot worse," Gov. Dave Heineman said in a teleconference Saturday.

Heineman visited the city of Chadron the day after 1,200 people evacuated their homes and firefighters successfully defended the Chadron State College campus. A subdivision on the south side of Chadron was briefly evacuated again Saturday.

Firefighters from local, state and federal agencies were battling the blazes, and helicopters and tanker planes were trying to slow the fires from the air, officials said.

Chadron Fire Chief Pat Gould choked up as he described how firefighters kept Friday night's fire from overtaking the town.

"The streets that lead from campus into Chadron became chimneys with the high winds we were experiencing and the embers blowing into town," Gould said. "We did a phenomenal job between local (volunteer fire departments) and the feds."

Firefighters burned some of the land between Chadron State College and the wildfire to eliminate fuel for the fire and keep it from reaching campus, said Marc Mullenix, the federal incident commander of the fire crews working there.

Sprinklers on the football practice fields were turned on full blast, and that helped provide a buffer between the wildfire and campus buildings, said Con Marshall, the college's sports information director.

The fire that threatened Chadron was moving southwest of town late Saturday afternoon. But Mullenix said a change in wind direction could put the town at risk again.

Elsewhere, a fire northwest of Rapid City, S.D., burned seven houses, officials confirmed Saturday. The fire had consumed about 4.6 square miles and was 80 percent contained; residents of 300 homes who were told to evacuate were allowed to return.

A lightning-caused wildfire near the Oregon border was 85 percent contained Saturday. Strong winds that firefighters feared would blow the blaze into a series of major power lines never materialized.

The blaze was burning a half mile east of California-Oregon Transmission Project power lines and three-quarters of a mile south of lines used by the Western Area Power Administration and Pacific Gas & Electric Co.

More than 300 firefighters were battling the blaze, which had charred more than three-quarters of a square mile in mountainous terrain about 200 miles north of Sacramento.

Farther north, a 2.3-square mile wildfire that broke out Saturday in Trinity County prompted authorities to ask hundreds of residents to voluntarily evacuate their homes on the west side of Weaverville. The blaze was approaching dozens of homes but had not damaged any by late Saturday, according to the Weaverville Fire District.

At the south end of the state, a wildfire in the Cleveland National Forest was 90 percent surrounded. The fire about 50 miles east of San Diego was about 26 square miles.

In Washington state, two wildfires were threatening vacation homes near Lake Cushman and Lake Chelan, with hundreds of people waiting for possible evacuation orders, fire officials said.

The fire was burning in the Wenatchee National Forest and the National Park Service's Lake Chelan National Recreation Area.

In southwest Montana, a fire six miles southwest of Victor grew to about 2.6 square miles, and officials warned nearby residents to prepare for a possible evacuation.

Firefighters in Oregon continued to battle a wildfire in the central part of the state that has grown to a little more than 7 square miles, officials said Saturday. The fire started from lightning last Sunday and is less than 5 percent contained.

About 500 residents from the Crossroads and Edgington communities near the tourist town of Sisters were evacuated Thursday.

The Deschutes County Sheriff's Office ordered an evacuation Saturday of another subdivision near Sisters because of the fire, sending more than 1,000 residents from their homes.

"Based upon current weather and fire conditions that include high winds and volatile fuels, we are ordering the evacuation," said Carl West, incident commander of the Northwest Oregon Interagency Incident Management Team.

In Maryland, 12 people were taken to hospitals Sunday for heat-related illnesses at an international scout jamboree, and about 40 needed to leave camp activities to cool off, officials said. None of the cases appeared serious.

The jamboree was organized by the Polish Scouters Association and included children from several countries, said Reed Blom, the director of Camp Spencer. About 1,500 people attended.

At a Boy Scout gathering in East Lansing, attendees were warned to be vigilant about the heat. Organizers had a medical team on hand.

"The Boy Scout motto is, 'Be prepared.' And I think our guys will be," said Clyde Mayer, director of the Order of the Arrow.

Highs in Michigan were only in the 80s on Sunday, but temperatures were expected to hit the upper 90s in parts of the state Monday and Tuesday, remaining well above normal until Thursday.

Thousands of heat-related illnesses were reported last summer at the Boy Scouts' national Jamboree. A federal report concluded leaders failed to provide campers with enough water and shade.

Oklahoma City was 102 degrees on Sunday, the 17th time this year the temperature has hit triple digits. The weather service issued a fire weather watch for western and central Oklahoma, areas that were also under a heat advisory through Tuesday.

Bismarck, N.D., hit a record 112 degrees on Sunday, its seventh day this month of triple-digit temperatures, said Ken Welk of the weather service. Highs on Monday were forecast in the mid- to upper 80s.

Heat warnings were issued Saturday for the Chicago and St. Louis areas through Tuesday evening. Minneapolis was under an excessive heat watch through Monday night.

The quake caused officials in southern Kyrgyzstan, the quake's epicenter, to shut down supplies of hydro-electric power to areas in the south of the country.

Repairs crews are checking for damage to the Toktogul reservoir and hydroelectric station, some 30 kilometers from the quake's epicenter.

No damage has been reported in Kazakhstan's Taraz region.

Uzbekistan has also not reported any damage.

He said based on previous events, a steady increase in sulfur dioxide emissions could culminate in an eruption. A sudden decrease after very high readings could also result in a large explosion, characterized by tall ash columns and pyroclastic flows, which are clouds of extremely hot gases, ash and other debris that race down mountain slopes at high speed, incinerating everything in their path.

Earthquakes may signal rising magma levels and the "inflation" of the mountain, all signs of a possible violent eruption, Solidum said.

Sulfuric emission was accompanied by 388 tremor episodes and lava flow, cascading down the southeast slopes, and advancing 100 meters farther to the Mabinit Channel at 6:30 Monday morning. A bright orange summit glow was exhibited on Sunday caused by lava coming from the crater.

Ground deformation is apparent caused by the continuing intrusion of magma inside the volcano, Phivolcs said.

On Sunday, dozens of residents, visitors from nearby towns and local tourists, flocked to the village of Mabinit on the outskirts of Legazpi city, capital of Albay, to watch in awe as lava fragments crumbled, exposing molten rocks beneath.

One man went up to one of the rocks to light a cigarette. Some posed for pictures with the smoldering lava deposit more than five stories high behind them as a backdrop.

Alert Level 3 Permanent Danger Zone (PDZ) is a "no man's land" in a seven-kilometer radius. Phivolcs reminds the residents to be vigilant of the hazards associated with either explosions from the summit or from the advancing lava flow in the southeast, especially in Barangays Mabinit, Mi-isi, Bonga, Matanag and Buyuan.

Residents are advised to be prepared for evacuation at anytime if Mayon's activity escalates further.

Lava from the volcano threatened to burn coconut groves along its slopes Sunday as dozens of awed onlookers flocked to the edge of the flow.

The volcano came to life in a mild eruption on June 14, oozing lava from the crater of the 2,474-meter mountain.(AP/Sunnex)

The team thinks the mini-volcanoes were created when cracks formed in the Earth's crust during the elastic bending of the northwestern Pacific plate, which is diving under the Kuril and Japan trenches. They think partially melted material from the upper mantle squeezed out of the cracks, to form the volcanoes.

"I was unbelievably excited to discover this volcanism," Hirano says. "The possibility had been proposed in the past, but had never been adequately documented."

Buoyant plumes

Volcanoes are thought to form in three settings: where tectonic plates are diverging (for instance at mid-ocean ridges); where tectonic plates are converging (in island arcs, for example); and in "hotpots" (a generic term for volcanic activity that cannot be attributed to plate tectonic movements. Hotspots are generally thought to be formed by hot, buoyant plumes rising rapidly from the boundary between Earth's core and the mantle.

The "new" volcanoes, which are actually between one and eight million years old, are not at plate boundaries. But neither were they formed by deep plumes.

When Hirano's team analysed the trace element geochemistry and compositions of noble gas isotopes in their volcanic flows, they concluded that the material originated in the asthenosphere - a layer of the mantle directly under Earth's crust. Samples of the flows were collected by submersibles.

Universal explanations

"These findings are probably the best evidence to date that not all chains of mid-plate volcanoes are formed by plumes," says Marcia McNutt of the Monterey Bay Aquarium Research Institute in Moss Landing, California, US, who wrote a commentary on the paper published in Science. "These findings do not mean that plumes don't exist at all - there may be some volcanic chains that are caused by plumes, but they are no longer a universal explanation."

The question remains whether this new type of volcanism could explain other volcanic hotspots. There are lava fields near Samoa and in Hawaii for which a flexing of the tectonic plate had been suggested as a cause. But these suggestions had not been documented well, and the studies were largely discounted by other researchers, according to Hirano.

Now, in the light of the new research, scientists will go back to observations for other volcano chains with a more critical eye, McNutt believes. "They'll look to see what observations were ignored or swept under the rug because they couldn't explain the finding in the context of plume theory."

Journal reference: Science (DOI: 10.1126/science.1128235 and 10.1126/science.1131298)

The whale was badly hurt when Fisheries officers found it, said department spokeswoman Cate Barratt.

"It was belly up as the tide went out, and its whole layer of skin was gone and it was quite badly blistered," said Barratt. "The prognosis for the animal was very dim, and the animal was ordered destroyed."

Barratt said when destroying such a large animal, shooting it is not unusual.

Fisheries Department experts also consulted Tonya Wimmer, a Halifax-area marine biologist who runs the Marine Animal Response Society.

"It was extremely sunburnt, and it's very clear this animal wouldn't have made it," said Wimmer.

"They overheat when they're out of water, and that's one of the main things that destroys an animal this time of year."

Wimmer said it's difficult to destroy animals as large as whales. Euthanasia drugs can take too long and pose a danger to other animals who eat the carcass.

"With an animal this size, [shooting it] is pretty much the only way you can do it other than letting nature take its course, which for this animal would be too painful," she said.

Wimmer said her group hopes to collect samples and examine the carcass before it is disposed of.

The Marine Animal Response Society tracks stranded marine animals, investigates why they become stranded or beached, and offers advice on how to deal with them.

"The majority of the Toowoomba community does not support the indirect potable reuse of recycled water," said Australia's parliamentary secretary for water, Malcolm Turnbull.

"I respect that decision. Reuse of recycled water for drinking purposes in the manner proposed is sustainable and it is safe. But, as I have said many times, it is not compulsory."

If residents had voted "yes," 25 percent of their drinking water would have come from recycled water in a A$68 million ($52 million) scheme. The water is filtered through a complex membrane in a process known as reverse osmosis.

Turnbull said recycling water was important for Australia as demand was expected to exceed supply from existing water sources in nearly all major Australian cities within the next 20 years.

"The culling on all 78 farms has already begun and we hope to finish them all by tonight," he said.

Charal said the outbreak in Nakohn Panom, 740 km (460 miles) northeast of Bangkok, might be caused by H5N1-infected egg trays taken from "the other side" of the border, in an apparent reference to Laos.

"These egg merchants were too lazy to swap eggs from their trays to those of their customers'. They just swapped the trays and that's how the disease spread to the village," he said.

A 17-year-old man died of bird flu on Monday in the northern province of Phichit, where authorities have slaughtered hundreds of birds and restricted poultry movement in a bid to stamp out Thailand's first outbreak in eight months.

The U.N. Food and Agriculture Organization (FAO) said on Friday the deadly virus was also found on a poultry farm in Laos, the country's first major outbreak since 2004.

The outbreak occurred on a commercial farm 25 km (15 miles) south of Vientiane where about 2,500 chickens died last week, according to state media reports.

The same farm experienced an outbreak in early 2004 when the virus swept through parts of Asia, including Communist-led Laos where most of its 5.6 million people live in remote rural areas.

The FAO was due to send a bird flu expert to Laos on Tuesday to assess the situation, an FAO official said.

Charal said the ministry instructed governors of provinces bordering Laos, Cambodia and Myanmar to step up surveillance on animals transferred from these countries -- where basic health care barely exists outside urban areas.