Minggu, 29 Mei 2011

Ribuan hektare Mangrove di Kalsel Rusak

Ribuan hektare Mangrove di Kalsel Rusak

Laporan Wartawan Banjarmasin Post, Choiruman

TRIBUNNEWS.COM, BANJARMASIN - Kondisi hutan mangrove di Kalimantan Selatan sangat memprihatinkan. Dari jumlah areal hutan mangrove yang mencapai 166 ribu hektare di sepanjang wilayah Kalsel, seluas 147 hektare kondisinya rusak berat. Padahal lebih separo hutan mangrove yang ada di Banua ini merupakan cagar alam.

Hal itu disampaikan Ketua komisi II DPRD Kalsel, Mohammad Ihsanuddin.
Dari data yang diterima pihaknya dan hasil pengecekan di lapangan, kondisi mangrove yang ada di daerah ini sangat rusak akibat adanya perambahan. Seperti untuk pembangunan pelabuhan khusus (Pelsus) maupun untuk tambak.

"Bahkan, dari luas hutan mangrove yang ada sebanyak 166 ribu hektare, hanya 19 ribu hektare saja yang kondisinya bagus. Selebihnya rusak parah, karena ditebang dan sudah alih fungsi," katanya.

Padahal, lanjut dia, keberadaan mangrove itu sangat bermanfaat. Selain mampu menahan abrasi wilayah, hutan mangrove tersebut menjadi tempat berkembangbiaknya ikan-ikan tanpa harus memberikan makanan alias alami.

Bahkan, daun mangrove tersebut juga bermanfaat untuk mencegah penularan flu burung. Menurut politisi asal Partai Keadilan Sejahtera (PKS) Kalsel, menceritakan seperti yang dikembangkan pemerintah daerah Sumatera Utara (Sumut).

Di saat semua daerah digegerkan dengan penularan virus mematikan tersebut, Pemda Sumut justru santai. Karena tak satupun hewan ternak di daerah itu yang ditemukan tertular virus tersebut, karena para peternaknya dengan rajin memberikan campuran makanan dengan daun mangrove tersebut.

"Ini pelajaran yan tidak pernah terpikir oleh kita. Pemda Sumut tetap santai saat virus flu burung mendera, katanya makanan ayam ataupun unggas cukup dicampur dengan daun mangrove tersebut," terangnya.

Oleh karena itu, imbuh dia, pihaknya meminta kepada dinas terkait untuk lebih intensif memberikan pengawasann terhadap hbutan mangrove tersebut. bahkan pihkanya bakal mengadendakan secara khusus untuk pembahasan perbaikan mangrove di Kalsel.

Termasuk tidak mudah memberikan perizinan usaha yang masuk dalam kawasan hutan mangrove tersebut. karena jika ada aktivitas di kawasan itu, secara otomatis keberadaan hutan itu bakal rusak.

"Padahal kalau untuk tambak tidak perlu dibabat. Karena para nelayan bisa memanfaatkan sela-sela pohon tersebut untuk pertambakan," timpal Burhanudin, anggota komisi II lainnya.


http://id.berita.yahoo.com/ribuan-hektare-mangrove-di-kalsel-rusak-100615669.html

Death toll from Joplin tornado is at least 139

Death toll from Joplin tornado is at least 139


Unidentified friends of Will Norton console each other before a news conference with family members at Freeman Hospital in Joplin, Mo. Saturday, May 2AP – Unidentified friends of Will Norton console each other before a news conference with family members at …

JOPLIN, Mo. – The numbers look increasingly bleak for families hoping for the best after a monster tornado that devastated the town of Joplin, with city officials saying death toll is at least 139. State officials say 100 people are still missing.

Thousands more people far beyond Joplin had been waiting for good news about a teen believed to have been ejected or sucked from his vehicle on the way home from graduation. Several social-networking efforts specifically focused on finding information about Will Norton.

But his family says he, too, is among the dead — found in a pond near where his truck was located.

"At least we know that he wasn't out there suffering," his aunt Tracey Presslor said, holding a framed portrait of her 18-year-old nephew at a news conference. "Knowing that he was gone right away was really a blessing for us."

Joplin City Manager Mark Rohr said Saturday during a news conference that the death toll rose by three to at least 142, but later revised that figure down to 139 without elaboration.

Mike O'Connell, a spokesman for the Missouri Department of Public Safety, told The Associated Press on Saturday that he could not confirm the city's updated death toll number. He said the state of Missouri currently places the death toll at 126, saying they have no reason to raise that number.

State officials say there are 142 sets of human remains at the morgue handling those killed by the storm and some could be from the same victim.

If the death toll does stand at 139, it would place this year's tornado death toll at 520 and make 2011 the deadliest year for tornadoes since 1950. Until now, the highest recorded death toll by the National Weather Service in a single year was 519 in 1953. There were deadlier storms before 1950, but those counts were based on estimates and not on precise figures.

On Saturday night, the Department of Public Safety made public a list of 73 people who had been confirmed dead and whose next of kin had been notified.

The tornado — an EF-5 packing 200 mph winds _also injured more than 900 people. Tallying and identifying the dead and the missing has proven a complex, delicate and sometimes confusing exercise for both authorities and loved ones.

Missouri officials said Saturday that the number of people unaccounted for stands at 100. The Missouri Department of Public Safety said that within that number, nine people have been reported dead by their families, but state officials are working to confirm those.

Newton County coroner Mark Bridges said most, if not all, of the people brought to the temporary morgue could be identified this weekend. He described officials there as "making real good progress."

After a mistake immediately after the storm — four people thought they had identified one person's body, only to be wrong — authorities are relying instead on dental records, photos and unique tattoos or piercings, Bridges said. They've also used DNA tests in a handful of cases, he said.

"We learned the hard way at the start," he said. "It's bad for the families."

Asked about calls to open the morgue to all families of the missing, Bridges said doing so would be impractical. He described the site as a number of dark, refrigerated trailers holding body bags.

"There's no place to let them into," he said.

There have been 1,333 preliminary tornado reports in the U.S. through May 27, officials said, while the average number of confirmed tornadoes in a single year during the past decade has been 1,274.

Presslor said Saturday that the family received confirmation of his death late Friday night. She said her nephew's body was not found sooner because there was so much debris in the pond.

Family members had previously told The Associated Press that Norton and his father were still on the road when the storm hit. Mark Norton urged his son to pull over, but the teen's Hummer H3 flipped several times, throwing the young man from the vehicle, likely through the sunroof.

Mark Norton remains in the hospital and is "having a really tough time" after being told his son's body was found, Presslor said.

About a dozen of Norton's classmates stood in the back of the room as she spoke. His funeral arrangements are pending.

Presslor thanked the thousands of people who posted good wishes for Norton on Facebook, Twitter and other social media sites, and thanked all those who helped look for him. She urged those volunteers to keep looking for other people still missing.

"Please don't give up," she said.

http://news.yahoo.com/s/ap/20110529/ap_on_re_us/us_joplin_tornado

Flooded Montana towns prepare for more water

Flooded Montana towns prepare for more water


Flooded homes and vehicles near Crow Agency, Mont. are seen Friday May 27, 2011. Recent flooding displaced hundreds of residents of the Crow Indian ReAP – Flooded homes and vehicles near Crow Agency, Mont. are seen Friday May 27, 2011. Recent flooding displaced …

HELENA, Mont. – Montana communities took advantage of a break in rainy weather to clear flood debris from homes and roadways as states downstream prepared for floodwaters from the higher elevations and releases from their own burgeoning dams.

A respite in weather that has brought as much as 8 inches of rainfall over a span of a few days to some areas of Montana had allowed waters to recede slightly in several flooded communities, giving emergency crews the chance Saturday to fix some water-damaged roads.

But it looked brief with the National Weather Service predicting up to 3 inches of rainfall from Sunday to Monday. Meteorologist Keith Meier also warned that high temperatures and melting snowpack in the Rocky Mountains next week would likely swell rivers for even longer.

"Take a little time to breathe today, figure out what you need to do but don't let your guard down," said Cheri Kilby, Disaster and Emergency Coordinator for Fergus County.

Authorities have already started releasing massive volumes of water from overburdened reservoirs. The releases coupled with the floodwaters have been predicted to cause flooding downstream, possibly in the Dakotas, Iowa, Nebraska, Kansas and Missouri.

The Army Corps of Engineers is increasing releases from Missouri River dams because of higher rain forecasts. In South Dakota, the revised release plan means water levels in Yankton, Dakota Dunes will be higher than previously expected, the governor said.

Gov. Dennis Daugaard advised residents to be ready to evacuate. About 17,000 people live in the two communities.

"We expect flooding in these communities to be significant," the governor said. "I urge property owners in these areas to begin to plan immediately for an evacuation and to take steps to protect themselves and their property."

Near Bismark, N.D., the U.S. Army Corps of Engineers planned to increase releases over the coming weeks at Garrison Dam, about 75 miles upstream on the Missouri River. Plans also called for releasing water at four other Missouri River reservoirs.

The Missouri River in Bismark was slightly below flood stage of 16 feet on Saturday, but well out of its banks in some parts of the city and nearby Mandan, and officials are building levees to protect the city from a flood stage of 21 feet.

North Dakota Gov. Jack Dalrymple also said that the Federal Emergency Management Agency had expanded its federal emergency declaration to include seven state counties and the Standing Rock Reservation as they fight rising water on the Missouri River.

A state of disaster also was declared Friday on the Fort Berthold Reservation by Three Affiliated Tribes Chairman Tex Hall, who said flooding had damaged homes and other buildings, swamped farmland and caused highways to erode.

FEMA issued an emergency declaration in early April for 14 counties hit with flooding.

In Montana, Gov. Brian Schweitzer deployed Montana National Guard soldiers to the Crow Reservation, one of the hardest hit areas, a day after touring the area.

The guardsmen were setting up unarmed security checkpoints on the Crow Reservation Saturday afternoon to help with emergency response. Crow Tribe officials earlier in the week requested National Guard aid after heavy rainfall put much of the reservation under water and left residents stranded.

Crow Chairman Cedric Black Eagle said the tribal government helped pump water out of flooded basements and clear off roads so families could return and start to repair their homes.

It was possible people would have to leave the reservation again if water levels began to rise again, he said.

To the northwest, the small agricultural town of Roundup seemed to retain much of its flood water and the Musselshell River level was hardly declining, emergency officials said. Road closures have cut the town off from all directions but the north.

Director of Disaster and Emergency services for Musselshell County Jeff Gates said people are still stranded around the town. Gates said there is little emergency crews can do at this point but provide people with supplies they need and wait for water to go down.

Gates said that doesn't look to be likely for quite a while.

He is concerned about the town running out of freshwater and residents are being told to conserve as much as they can.

Businesses are having a hard time getting supplies and residents are mostly helpless to do anything about several feet of water on the southern side of town.

The businesses that have managed to stay open have seen quite a few customers, frustrated with nothing else to do but wait out the water.

Everett Reaves, owner of the Keg Bar in Roundup said a number of people are coming out to his bar.

"When things are down, people go to places like this to forget about it," he said.

Blaine Tull, who runs the Pioneer Cafe in Roundup with his wife, had a different take on the situation and the water conservation.

"Ain't no sense in getting frustrated with something you can't change," he said

http://news.yahoo.com/s/ap/20110529/ap_on_re_us/us_western_flooding

Gempa 6,3 SR Goyang Lampung, Tidak Berpotensi Tsunami

Minggu, 29/05/2011 00:27 WIB
Gempa 6,3 SR Goyang Lampung, Tidak Berpotensi Tsunami
Fajar Pratama - detikNews
Gempa 6,3 SR Goyang Lampung, Tidak Berpotensi Tsunami
BMKG

Jakarta
- Gempa bumi kembali mengguncang kawasan Indonesia. Kali ini gempa berkekuatan 6,3 Skala Richter (SR) menggoyang Lampung dan sekitarnya.

Berdasarkan informasi yang diperoleh dari Badan Metereologi Klimatologi dan Geofisika (BMKG), gempa terjadi pukul 00.07 WIB, Minggu (29/5/2011).

Pusat gempa berjarak 119 Km sebelah barat daya Lampung, tepatnya di koordinat 6.01 LS,103.24 BT. Sementara kedalaman gempa berjarak 10 km.

BMKG memastikan gempa tersebut tidak berpotensi mendatangkan gelombang tsunami. Belum ada laporan korban atau kerusakan akibat peristiwa ini.


(fjr/mad)

Science can't design away tornadoes' deadly threat

Science can't design away tornadoes' deadly threat


In this April 27, 2011 file photo, a tornado moves through Tuscaloosa, Ala.  Storm science has greatly improved tornado warnings in recent years. But AP – In this April 27, 2011 file photo, a tornado moves through Tuscaloosa, Ala. Storm science has greatly …

WASHINGTON – Storm science has greatly improved tornado warnings in recent years. But if that's led anyone into a sense of security, that feeling has taken a beating in recent weeks.

Super Outbreak 2011, on April 25-28, killed more than 300 people in the South and Midwest. Less than a month later, a devastating tornado took more than 130 lives around Joplin, Mo. This is now the deadliest year for tornadoes since 1950, based on an assessment of National Weather Service figures.

This despite warnings of as much as 20 minutes, thanks to improved weather radar installed across the country in the 1990s. Before that, tornado warnings often weren't issued until a twister was sighted on the ground.

Scientists see a variety of factors that helped make this year's twisters deadlier — from La Nina to public complacency, from global warming to urban sprawl.

"We thought for the longest time physical science could get us by ... that we could design out of disaster," said meteorology professor Walker Ashley of Northern Illinois University. Now scientists are finding they need to take human nature into account.

What is clear is that certain factors add to the risk of death. The most vulnerable folks are those living in mobile homes and houses without basements. For a variety of reasons, a lot of homes don't have basements.

Twisters occurring on weekends — like the Joplin tornado — and at night tend to be greater killers because they catch people at home. At night, twisters are harder to see and sleeping people may not hear a warning.

Those less likely to be killed in a storm tend to be more educated and to have a plan in place beforehand.

In Sedalia, Mo., 30-year-old Sean McCabe had the right idea when the tornado struck, heading to the basement. He said the storm shoved him down the final flight of steps. He had scrapes and cuts on his hands, wrists, back and feet. Blood was visible in the house, and much of the roof of the house was gone.

"I saw little debris and then I saw big debris, and I'm like OK, let's go," said McCabe.

Having a plan was a lifesaver for Tuscaloosa's LaRocca Nursing Home in Alabama. As the storm howled, four dozen residents massed in the hallways as trees crashed down and a cloud of dust rained upon them. When the dust settled, the staff realized their drills had paid off. Not one patient was killed, and the worst injury among them was a bruise.

Hundreds have not been so lucky, with more than 500 deaths and counting so far this year, a toll not seen in more than a half-century.

The toll for 2011 is now at least 520 people, exceeding the previous highest recorded death toll in a single year of 519 in 1953. There were deadlier storms before 1950, but those counts were based on estimates and not on precise figures.

The National Weather Service said 58 tornadoes touched down in Alabama on April 27, killing 238 people in that state alone and injuring thousands. Scores died in other states from twisters spawned by the same storm system. Put together, emergency management officials say the twisters left a path of destruction 10 miles wide and 610 miles long, or about as far as a drive from Birmingham to Columbus, Ohio.

Statewide, Alabama officials estimate there was enough debris to stack a football field a mile high with rubble.

Contributing to the massive loss of life is the growth of urban areas, suggested Marshall Shepherd, a professor of atmospheric science at the University of Georgia.

"Historically, the central business districts of cities have not been hit that frequently," he explained. But as you increase the land area covered by homes and businesses, he said, "you're increasing the size of the dartboard."

An expanding population does increase exposure to the danger, agreed Ashley, who fears deaths could begin to rise in the future as a result of sprawl and more people living in vulnerable residences such as mobile homes.

If the Tuscaloosa and Joplin tornadoes had each been a few miles to the south, on farmland, little would be heard about them, Ashley said, but when extremely violent tornadoes mingle with urban sprawl "you're going to have a disaster."

"I hope this will be an outlier year, very much like Katrina was to hurricanes," he said in a telephone interview from a field trip to chase tornadoes.

But no one can guarantee that, and weather experts are becoming increasingly concerned about how people respond to tornado warnings.

"A lot of it is complacency," Ashley said. "The population seems to be becoming desensitized to nature. I don't know why."

Studies have shown that 15 to 20 minutes is the most effective amount of warning time, and longer warning times can increase deaths. Weather experts aren't sure why, but worry that people think that if a twister hasn't appeared in a certain amount of time, it must have been a false alarm.

Yet a long-track tornado can be on the ground for 30 miles.

"If you have a basement, you don't need 20 minutes warning, but if you are in a mobile home park you may need more than 20 minutes to find a shelter," commented Alan W. Black, a University of Georgia doctoral student and co-author with Ashley of a recent study of tornado and wind fatalities.

Jerry Brotzge, a research scientist at the Center for Analysis & Prediction of Storms, University of Oklahoma, said many people who hear warnings will look outside to see if they can see the tornado — "they need some kind of confirmation, they want to see it."

But the Joplin tornado was at least partly rain-wrapped, meaning that a powerful rainstorm obscured it from some directions and "they wouldn't have seen it coming."

"Even when people are sheltered in their homes, if they are not underground they can die," Brotzge added.

But asking people to evacuate an area is also a difficult decision, he said, "what if you have a traffic jam and the tornado hits that."

Ashley concluded: "The take-home is, people have to take personal responsibility for their lives."

Why there have been so many tornado threats this year is harder to say.

Viewing pictures of the tornado aftermath it's hard to overestimate the power of such storms, and records bear out how strong they can be.

"You see pictures of World War II, the devastation and all that with the bombing. That's really what it looked like," said Kerry Sachetta, the principal of a flattened Joplin High School. "I couldn't even make out the side of the building. It was total devastation in my view. I just couldn't believe what I saw."

And that movie image a few years ago was no joke: A cow was transported 10 miles by a twister in Iowa in 1878 and a tornado in Minnesota moved a headstone three miles in 1886.

One Joplin resident said a picture that was sucked off his house's wall was found in Springfield, 70 miles away. An insurance policy was found more than 40 miles from its original residence in Oklahoma in 1957 and a 210-mile trip was taken by a canceled check in Nebraska in 1915, according to a study several years ago by researchers at the University of Oklahoma and St. Louis University.

Typically, tornadoes spawn in the clash between warm, moist air from the Gulf of Mexico and cooler, dry air from the north and west — conditions that mark Tornado Alley in the Midwest and South, the most common breeding grounds for twisters.

Factors in this year's excess may include La Nina, a periodic cooling of the tropical Pacific Ocean which can affect weather worldwide. In a La Nina year there tend to be more tornadoes than average. If that is a factor, the good news is that La Nina is weakening and is expected to end in a month or so.

The meandering jet stream high in the atmosphere that directs the movements of weather also has been in a pattern that encourages warm Gulf air to move in and clash with drier air masses.

While studies of global warming have suggested it could cause more and stronger storms, National Weather Service Director Jack Hayes isn't ready to blame climate change — at least not yet — saying it's too soon to link individual events with the ongoing warming.

Tornado researcher Howard B. Bluestein of the University of Oklahoma says his best guess is this unusual outburst of twisters is due to natural variability of the weather.

"Sometimes you get a weather pattern in which the ingredients for a tornado are there over a wide area and persist for a long time. That's what we're having this year," he said.

"If we see this happen next year and the following year and the following year," then maybe climate change could be to blame, he said.

Whatever the reasons it's an extraordinary year for tornadoes and the worst may not be over. May is usually the peak month, but June traditionally gets lots of twisters, and they can occur in any month.

"You can never completely breathe easy," concluded Russell Schneider, director of the government's Storm Prediction Center in Norman, Okla.

___

Associated Press writers Nomaan Merchant, Alan Scher Zagier and Jim Salter in Joplin, Mo.; Jay Reeves in Birmingham, Ala.; and Kristi Eaton in Norman, Okla., contributed to this report.

http://news.yahoo.com/s/ap/20110528/ap_on_sc/us_sci_year_of_the_tornado

Science can't design away tornadoes' deadly threat

Science can't design away tornadoes' deadly threat


In this April 27, 2011 file photo, a tornado moves through Tuscaloosa, Ala.  Storm science has greatly improved tornado warnings in recent years. But AP – In this April 27, 2011 file photo, a tornado moves through Tuscaloosa, Ala. Storm science has greatly …

WASHINGTON – Storm science has greatly improved tornado warnings in recent years. But if that's led anyone into a sense of security, that feeling has taken a beating in recent weeks.

Super Outbreak 2011, on April 25-28, killed more than 300 people in the South and Midwest. Less than a month later, a devastating tornado took more than 130 lives around Joplin, Mo. This is now the deadliest year for tornadoes since 1950, based on an assessment of National Weather Service figures.

This despite warnings of as much as 20 minutes, thanks to improved weather radar installed across the country in the 1990s. Before that, tornado warnings often weren't issued until a twister was sighted on the ground.

Scientists see a variety of factors that helped make this year's twisters deadlier — from La Nina to public complacency, from global warming to urban sprawl.

"We thought for the longest time physical science could get us by ... that we could design out of disaster," said meteorology professor Walker Ashley of Northern Illinois University. Now scientists are finding they need to take human nature into account.

What is clear is that certain factors add to the risk of death. The most vulnerable folks are those living in mobile homes and houses without basements. For a variety of reasons, a lot of homes don't have basements.

Twisters occurring on weekends — like the Joplin tornado — and at night tend to be greater killers because they catch people at home. At night, twisters are harder to see and sleeping people may not hear a warning.

Those less likely to be killed in a storm tend to be more educated and to have a plan in place beforehand.

In Sedalia, Mo., 30-year-old Sean McCabe had the right idea when the tornado struck, heading to the basement. He said the storm shoved him down the final flight of steps. He had scrapes and cuts on his hands, wrists, back and feet. Blood was visible in the house, and much of the roof of the house was gone.

"I saw little debris and then I saw big debris, and I'm like OK, let's go," said McCabe.

Having a plan was a lifesaver for Tuscaloosa's LaRocca Nursing Home in Alabama. As the storm howled, four dozen residents massed in the hallways as trees crashed down and a cloud of dust rained upon them. When the dust settled, the staff realized their drills had paid off. Not one patient was killed, and the worst injury among them was a bruise.

Hundreds have not been so lucky, with more than 500 deaths and counting so far this year, a toll not seen in more than a half-century.

The toll for 2011 is now at least 520 people, exceeding the previous highest recorded death toll in a single year of 519 in 1953. There were deadlier storms before 1950, but those counts were based on estimates and not on precise figures.

The National Weather Service said 58 tornadoes touched down in Alabama on April 27, killing 238 people in that state alone and injuring thousands. Scores died in other states from twisters spawned by the same storm system. Put together, emergency management officials say the twisters left a path of destruction 10 miles wide and 610 miles long, or about as far as a drive from Birmingham to Columbus, Ohio.

Statewide, Alabama officials estimate there was enough debris to stack a football field a mile high with rubble.

Contributing to the massive loss of life is the growth of urban areas, suggested Marshall Shepherd, a professor of atmospheric science at the University of Georgia.

"Historically, the central business districts of cities have not been hit that frequently," he explained. But as you increase the land area covered by homes and businesses, he said, "you're increasing the size of the dartboard."

An expanding population does increase exposure to the danger, agreed Ashley, who fears deaths could begin to rise in the future as a result of sprawl and more people living in vulnerable residences such as mobile homes.

If the Tuscaloosa and Joplin tornadoes had each been a few miles to the south, on farmland, little would be heard about them, Ashley said, but when extremely violent tornadoes mingle with urban sprawl "you're going to have a disaster."

"I hope this will be an outlier year, very much like Katrina was to hurricanes," he said in a telephone interview from a field trip to chase tornadoes.

But no one can guarantee that, and weather experts are becoming increasingly concerned about how people respond to tornado warnings.

"A lot of it is complacency," Ashley said. "The population seems to be becoming desensitized to nature. I don't know why."

Studies have shown that 15 to 20 minutes is the most effective amount of warning time, and longer warning times can increase deaths. Weather experts aren't sure why, but worry that people think that if a twister hasn't appeared in a certain amount of time, it must have been a false alarm.

Yet a long-track tornado can be on the ground for 30 miles.

"If you have a basement, you don't need 20 minutes warning, but if you are in a mobile home park you may need more than 20 minutes to find a shelter," commented Alan W. Black, a University of Georgia doctoral student and co-author with Ashley of a recent study of tornado and wind fatalities.

Jerry Brotzge, a research scientist at the Center for Analysis & Prediction of Storms, University of Oklahoma, said many people who hear warnings will look outside to see if they can see the tornado — "they need some kind of confirmation, they want to see it."

But the Joplin tornado was at least partly rain-wrapped, meaning that a powerful rainstorm obscured it from some directions and "they wouldn't have seen it coming."

"Even when people are sheltered in their homes, if they are not underground they can die," Brotzge added.

But asking people to evacuate an area is also a difficult decision, he said, "what if you have a traffic jam and the tornado hits that."

Ashley concluded: "The take-home is, people have to take personal responsibility for their lives."

Why there have been so many tornado threats this year is harder to say.

Viewing pictures of the tornado aftermath it's hard to overestimate the power of such storms, and records bear out how strong they can be.

"You see pictures of World War II, the devastation and all that with the bombing. That's really what it looked like," said Kerry Sachetta, the principal of a flattened Joplin High School. "I couldn't even make out the side of the building. It was total devastation in my view. I just couldn't believe what I saw."

And that movie image a few years ago was no joke: A cow was transported 10 miles by a twister in Iowa in 1878 and a tornado in Minnesota moved a headstone three miles in 1886.

One Joplin resident said a picture that was sucked off his house's wall was found in Springfield, 70 miles away. An insurance policy was found more than 40 miles from its original residence in Oklahoma in 1957 and a 210-mile trip was taken by a canceled check in Nebraska in 1915, according to a study several years ago by researchers at the University of Oklahoma and St. Louis University.

Typically, tornadoes spawn in the clash between warm, moist air from the Gulf of Mexico and cooler, dry air from the north and west — conditions that mark Tornado Alley in the Midwest and South, the most common breeding grounds for twisters.

Factors in this year's excess may include La Nina, a periodic cooling of the tropical Pacific Ocean which can affect weather worldwide. In a La Nina year there tend to be more tornadoes than average. If that is a factor, the good news is that La Nina is weakening and is expected to end in a month or so.

The meandering jet stream high in the atmosphere that directs the movements of weather also has been in a pattern that encourages warm Gulf air to move in and clash with drier air masses.

While studies of global warming have suggested it could cause more and stronger storms, National Weather Service Director Jack Hayes isn't ready to blame climate change — at least not yet — saying it's too soon to link individual events with the ongoing warming.

Tornado researcher Howard B. Bluestein of the University of Oklahoma says his best guess is this unusual outburst of twisters is due to natural variability of the weather.

"Sometimes you get a weather pattern in which the ingredients for a tornado are there over a wide area and persist for a long time. That's what we're having this year," he said.

"If we see this happen next year and the following year and the following year," then maybe climate change could be to blame, he said.

Whatever the reasons it's an extraordinary year for tornadoes and the worst may not be over. May is usually the peak month, but June traditionally gets lots of twisters, and they can occur in any month.

"You can never completely breathe easy," concluded Russell Schneider, director of the government's Storm Prediction Center in Norman, Okla.

___

Associated Press writers Nomaan Merchant, Alan Scher Zagier and Jim Salter in Joplin, Mo.; Jay Reeves in Birmingham, Ala.; and Kristi Eaton in Norman, Okla., contributed to this report.

http://news.yahoo.com/s/ap/20110528/ap_on_sc/us_sci_year_of_the_tornado