NEW ZEALAND EARTHQUAKE 

A powerful earthquake shook the New Zealand city of Christchurch on Tuesday, killing at least 65 people and trapping countless others under heaps of rubble. The magnitude-6.3 quake hit just before 1 p.m. local time (7 p.m. Monday ET), triggering a wave of collapsing buildings and buckling roads that immediately plunged the city into chaos. As one witness tells CNN, there were "windows blowing out, bricks falling down, people screaming, the whole nine yards. ... It was bloody serious."

As rescue crews now scramble to find survivors, the 65 confirmed deaths already make this the second-deadliest earthquake in New Zealand history, behind only a magnitude-7.9 quake that killed 256 in February 1931. Unconfirmed reports suggest the death toll from Tuesday's temblor may be more than 90, and some estimates range as high as 1,000. The fatalities include "two buses crushed by falling buildings," according to a statement from the Christchurch police, which adds that "the central city is currently being evacuated, as reports are received of widespread damage to buildings and infrastructure. Multiple fatalities have been reported at several locations." Much of the city is also without electricity or running water, and Mayor Bob Parker has warned residents to conserve clean water. "Do not shower, do not take a bath, do not flush your loo," he said in a press conference Tuesday. "Dig a hole in the back yard if that is what it takes, and save your water for drinking. Our focus is on rescue."

The earthquake's epicenter was located 3 miles underground and about 12 miles southeast of Christchurch, not far from an even stronger tremor that also hit the area less than six months ago. The Sept. 4 quake was a magnitude-7.1, but its epicenter was deeper and farther from the city, so the damage wasn't as severe. It also struck at night, while Tuesday's quake hit in the middle of a workday. "To be honest, it's pretty grim," says Ian Stuart, a reporter for the New Zealand Press Association. "The last earthquake in September didn't kill anyone because people were home asleep when it struck. This one hit when the streets were filled with people."

(Sources: New Zealand Herald, Los Angeles Times, CNN, Associated Press)

DAMMING EVIDENCE 

Communities across the U.S. sit in the shadow of a looming disaster, the New York Times reports today, as the country's aging dams increasingly threaten to unleash a wave of destruction on people who live in their spillways. More than 4,400 of the 85,000 dams nationwide are considered susceptible to failure, according to the Association of Dam Safety Officials, but it would cost billions to repair them all — an unlikely outcome at a time of sweeping government cutbacks. 

The Times highlights the example of Lake Isabella, Calif., a town of 4,000 people perched perilously below the 57-year-old Lake Isabella Dam (pictured above). The Hoover Dam this is not — instead of a towering wall of reinforced concrete, the Lake Isabella Dam consists of two earthen walls that are already known to leak. It was built before the adoption of many modern dam-safety standards, such as the practice of installing drains and filters to fight erosion and divert seepage. Engineers also underestimated how much water is impounded upstream in the Kern River — the sprawling watershed includes Mount Whitney, the tallest peak in the Lowest 48 states, and excessive rain and snow at higher elevations could overwhelm the dam. "We could not release the water fast enough" during a maximum flood, the dam's manager tells the Times. "It would overtop." In addition to flooding the small town of Lake Isabella, such a flood would also endanger the 340,000 residents of Bakerfield, located 40 miles downstream in the Kern River Canyon. If the dam failed, Bakersfield could be buried under 30 feet of water.

But perhaps the greatest single threat to residents downstream from the Lake Isabella Dam isn't the dam itself — it's the ground underneath it. Engineers knew they were building the dam on an earthquake fault, but seismologists at the time were convinced the fault was dormant. Well, turns out they were wrong: Scientists have since proven that three significant quakes have occurred there in the past 10,000 years. "We've got a fairly active fault on our hands," one dam official says. Lake Isabella may be an extreme example, but as the Times highlights, thousands of other dams around the country are similarly poised to wreak havoc on their surroundings. "It's not just the loss of life, potentially," says David Serafini with the U.S. Army Corps of Engineers. "It's the economic damages and the environmental damage, too."

(Source: New York Times)

SNAKE-BIT 

The planet's snakes are becoming more dangerous, the BBC reports today, thanks to encroaching human populations and evolutionary pressure to be more poisonous. The BBC cites several recent studies, including research that suggests far more people are bitten by snakes each year than officially reported — possibly as many as 5.5 million, resulting in roughly 400,000 amputations and anywhere from 20,000 to 125,000 human deaths. Especially in remote areas and undeveloped countries, this amounts to a global public health crisis, some experts say.

Part of the problem is that people are colonizing more and more of snakes' habitats, forcing the animals into increasingly frequent showdowns. But it's not just that we're encountering snakes more often — the snakes themselves are also becoming more deadly, according to a study published last month in the journal Toxicon. Researchers found that some ground squirrels in California have evolved blood than can neutralize specific toxins in rattlesnake venom, triggering an arms race that also rewards snakes for evolving more potent poison. And that's exactly what snakes like the eastern diamondback rattlesnake (pictured above) appear to be doing: By studying the snake's genetic code for the proteins that make up its venom, the researchers discovered that all the genes are undergoing "positive selection," the first evidence of such an evolutionary change. "To find nearly all of the genes for a single trait being continually developed in this way is truly remarkable," study co-author Darin Rokyta of Florida State University tells the BBC.

While it's not entirely clear why the snakes are evolving to become more venomous, there's a good chance it's nature's way of helping them overcome the poison-proof blood in their prey, Rokyta says. While that may just be part of a natural cycle, however, it doesn't bode well for humans. "From the perspective of humans, who are not competing in that arms race, the possibility exists that toxicity would increase over time," he warns.

(Source: BBC News)

DYING DOLPHINS 

Baby dolphins are washing ashore in Mississippi and Alabama at 10 times the animals' normal infant-death rate, the Biloxi Sun-Herald reports, raising fears along the beleaguered coast that remnants of the 2010 Gulf oil spill might be responsible. "We shouldn't really jump to any conclusions until we get some results" from autopsies, says Moby Solangi, director of the Institute of Marine Mammal Studies, which is performing the autopsies. "But this is more than just a coincidence."

At least 17 young dolphins have been collected in the two states, either having been aborted before reaching maturity or having died shortly after birth, the Sun Herald reports. Oil from last summer's spill did reach into many of Mississippi's and Alabama's shallow-water bays, where Gulf dolphins are known to breed and give birth. Dolphins breed in the spring, carrying their young for 11 to 12 months before giving birth, and this spring will mark the first birthing season for dolphins living in the Gulf since the disastrous spill, which unleashed some 5 million barrels of crude into the sea. 

One or two dead infants are typically found per month every January and February in Mississippi and Alabama, before birthing season hits its peak in March and April. But what's happening this year is significantly different, Solangi says. "For some reason, they've started aborting or they were dead before they were born," Solangi said. "The average is one or two a month. This year we have 17 and February isn't even over yet."

(Source: Biloxi Sun-Herald)

THIS DAY IN HISTORY

British Parliament tackles "smoke nuisance," Florida suffers its deadliest tornado outbreak, and more.

Russell McLendon

Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.

Photo (earthquake damage in Christchurch on Feb. 22): ZUMA Press

Photo (Lake Isabella Dam covered in snow): ZUMA Press

Photo (eastern diamondback rattlesnake): Dave Martin/AP

Photo (adult and baby spotted dolphin in the Atlantic): ZUMA Press

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.