Stories tagged natural disaster

Feb
17
2014

Kilauea at night: a massive magma chamber has been detected beneath the volcano's East Rift Zone.
Kilauea at night: a massive magma chamber has been detected beneath the volcano's East Rift Zone.Courtesy Mark Ryan
Researchers from the University of Miami Rosentiel School of Marine and Atmospheric Science have detected a new, massive magma chamber beneath Kilauea, the most active volcano in the world.

By analyzing seismic waves that traveled through the volcano, scientists from the school's geology and geophysics departments have been able to piece together a 3-dimensional velocity model of what's taking place deep below the volcano's caldera.

"It was known before that Kilauea had small, shallow magma chambers," said Guoqing Lin, lead author of the study. "This study is the first geophysical observation that large magma chambers exist in the deep oceanic crust below."

Located in oceanic crust between 5 and 6.8 miles beneath the volcano's East Rift Zone, the new chamber has been determined to be several kilometers in diameter. The seismic data also revealed that it's lava is composed of a slushy mixture of about 10 percent magma and 90 percent crystal.

According to co-author and professor of geology and geophysics, Falk Amelung, the information is useful in understanding magma bodies and a high priority for the researchers because of the possible hazards created by the volcano.

"Kilauea volcano produces many small earthquakes and paying particular attention to new seismic activity near this body will help us to better understand where future lava eruptions will come from," he said.
Kilauea has been active for more than 30 years and is located in Hawaii Volcanoes National Park on the Big Island of Hawaii.

The paper appeared in a recent edition of the journal Geology.

SOURCES and LINKS
Science News story
LiveScience story
2007 video of Kilauea erupting
More about Kilauea

Feb
11
2014

3D perspective of Decorah Impact Structure
3D perspective of Decorah Impact StructureCourtesy Public domain via USGS
By studying magnetic and electrical data, geologists have found further evidence that the town of Decorah, Iowa is built upon an ancient impact crater created around 460 million years ago.

Site map of Decorah crater
Site map of Decorah craterCourtesy Vkil via Wikipedia Creative Commons
Decorah is located in northeast Iowa near the Minnesota border about 150 miles south of Minneapolis. Scientists think the Decorah Impact Structure resulted from the same meteorite barrage - known as the Ordovician meteor event - that produced similarly-aged craters found in Oklahoma, Wisconsin, and the Slate Islands in Lake Superior. The Decorah crater lines up nicely with the others.

The first evidence that an ancient crater might exist under Decorah came in 2008 when well-drilling cores from the area collected and examined by Iowa's Department of Natural Resources and Geological and Water Survey indicated that a wide-ranging layer of an unusual type of shale set beneath the surface and encircled the town. Recent aerial geophysical measurements (both gravity and electrical magnetic) by the US Geological Survey and other agencies, including the Minnesota Geological Survey, affirmed the crater's existence.

The unusual shale layer is situated 50 feet under the bed of the Upper Iowa river and was probably deposited after the crater's creation when an ancient seaway invaded the area and filled in the basin with mud and sediment. Shocked quartz found in the rock layer directly beneath the shale adds further evidence that some sort of major impact took place. Shocked quartz is a highly stressed and shattered quartz produced only one of two ways: either by a bolide impact or from a nuclear blast. The impact that created the Decorah structure is estimated to have released the energy equal to the blast of 100 megatons of TNT. To put things in perspective, the nuclear bomb dropped on Hiroshima during World War II was equal to 15 kilotons of TNT. One megaton equals 1000 kilotons so the bolide blast in Decorah would have released the energy of more than 6500 Hiroshima bombs!

Paleobiologist Bevan French, an adjunct professor at the Smithsonian Institution's National Museum of Natural History studied quartz samples from the underlying layer of breccia and concluded they held characteristics indicative of an extra-terrestrial impact event.
When it slammed into Earth, the Decorah impactor created a 3.5 mile-in-diameter crater in the planet's surface and shattered existing layers of Early Ordovician and Cambrian rocks pushing them deeper underground. Several other meteor craters discovered on earth date back to around the same time period 450 to 470 million years ago, causing French to wonder if the Decorah crater should be included in that spike in impact frequency.

According to French the shale above the breccia layer is very well preserved and contains "a very fascinating biological assemblage,"which could also be of interest to paleontologists.

"Finding structures like these and being able to study them in the geological context," French said, "is going to yield a lot of very fascinating information about the relations between the terrestrial system and the extraterrestrial influences."

Sign of demise and new beginnings: A distinct layer of white clay in southern Colorado rock exposure (and found elsewhere around the world) marks the end of the dinosaurs (non-avian, anyway) and the beginnings of the reign of mammals.
Sign of demise and new beginnings: A distinct layer of white clay in southern Colorado rock exposure (and found elsewhere around the world) marks the end of the dinosaurs (non-avian, anyway) and the beginnings of the reign of mammals.Courtesy Mark Ryan
Has past life on Earth been influenced by these impacts? If you consider the Chicxulub impact crater in the Yucatán Peninsula of Mexico and its alleged effect on non-avian dinosaurs at the end of the Cretaceous Period, you have to wonder if similar impact events weren't responsible for other extinctions and biological radiations during Earth's long history.

SOURCE and LINKS

USGS story
Wunderground news story
Live Science report
Ordovician Meteor Event
Tiny Traces of Big Asteroid Breakup

Mother Nature brings it in 2013!

by Anonymous on Jan. 01st, 2014

EarthSky.org presents 2013's best weather videos on their website. Highlights include the massive flooding in Colorado, the destruction caused by the Super Typhoon Haiyan in the Philippines, and the seemingly endless highway pile-up near Germantown, Wisconsin. Especially terrifying is watching the May 20th Moore tornado grow from a small, ropey twister into a monster F5 killer storm in just a matter of minutes.

Mount Etna, located on the Italian island of Sicily, has been very active lately, as seen in this spectacular video by Boris Behncke, a researcher with Italy's National Institute of Geophysics and Volcanology. The stratovolcano is formed along the northern boundary of the African Plate as it collides with the Eurasian Plate. The shots of the exploding lava bubbles are fantastic and are reminiscent of a Fourth of July fireworks display. The images with the setting Moon are serenely beautiful. Etna is also blowing some great smoke rings!

In other volcano news, the rumblings of a new volcano have been detected under a half-mile thick sheet of ice in West Antarctica. Using seismograph data gathered from several field sites across Antarctica researchers - led by Prof. Doug Weins and PhD student Amanda Lough of Washington University in St. Louis, Missouri - think the volcano could be the newest in a chain of volcanos migrating under the ice-covered continent. Radar images gathered by researchers from the University of Texas have confirmed volcanic ash encased in the ice near the source of the detected activity. The seismic rumblings originate somewhere between 6 and 9 miles beneath the bedrock surface, too deep to be caused by sub-surface glacial movement or even tectonic activity. The study appears in the advanced online issue of Nature Geoscience.

SOURCE
Science Daily story

For a long time, scientists have known a major volcano complex was under the Pacific Ocean off the coast of Japan. But upon further inspection, they've discovered it's one huge volcano, measuring 280 miles by 400 miles across. You can read more about this huge discovery right here.

May
21
2013

More details are starting to emerge from the enormous tornado to rip through Oklahoma yesterday. Wind speeds were measured over 200 miles per hour. As of Tuesday morning, authorities had put the death toll at 24 but rescue crews were continuing to sort through the rubble looking for more casualties.

Here are a couple YouTube posts from storm chasers who were on the scene for yesterday's devastating tornado in Moore, Oklahoma. Listening to their voices, you can really get a feel for the huge magnitude of this tornado.

Oklahoma tornado paths: Three tornadoes have taken vary similar courses near Oklahoma City in the past 15 years.
Oklahoma tornado paths: Three tornadoes have taken vary similar courses near Oklahoma City in the past 15 years.Courtesy Oklahomanick
This map shows that three major tornadoes have taken very similar paths through this section of Oklahoma in the past 15 years, all occurring in May. The May 3, 1999 tornado killed 36 people and was rated EF-5, the strongest ranking on the tornado scale. The May 8, 2003 tornado was rated EF-4, but no one was killed. It is almost a certainty that the 2013 tornado will also be rated EF-5.

Click here to access an interactive slider graphic showing before and after aerial views of the destroyed Plaza Towers Elementary School building.

Satellite view: This satellite image shows the storm system that spawned the deadly tornado.
Satellite view: This satellite image shows the storm system that spawned the deadly tornado.Courtesy NOAA
NOAA (National Oceanic and Atmospheric Administration) captured this image of the storm system that spawned the tornado that hit Moore, Oklahoma. The storms’ violent updrafts sucked in air that shot up 40,000-50,000 feet or more into the atmosphere. The bubbly white structures you see in the image are known as overshooting cloud tops and are textbook features of violent thunderstorms.

A couple months ago, USA Today reported on global climate change's impact on tornadoes. You can read it here. Trying to draw conclusions about the impacts to this type of weather is twisted, to say the least.

Weather.com's Greg Forbes surveys the damage and gives his insights on the strength of the Oklahoma tornado.

Minnesota-based meteorologist Paul Douglas today gives some great analysis, and some amazing radar images, in the Start Tribune today on why this storm turned out to be so big and powerful. He also reviews the good and the better weather apps to have on your phone or mobile device to help you know when bad weather is coming.

Storm shelter: This commercially made storm shelter made of steel can hold up to six people.
Storm shelter: This commercially made storm shelter made of steel can hold up to six people.Courtesy Survive-a-storm
National Geographic shares information about how uncommon it is for tornadoes to hit developed, populated areas along with some of the basic science on what makes tornadoes occur.

USA Today reports that the phone is ringing off the hook for this tornado shelter sales company. A 4-by-6 steel shelter that can hold up to six people runs about $4,000. The demand is highest in the southern states where most homes are built without basements.

And here's the link to MDR's earlier post on the tornado, showing its movement in time lapse photography.

The massive tornado that tore through Moore, Oklahoma today is estimated to have been between 1 to 2 miles wide (!) and stayed on the ground for about 40 minutes. As of this writing it's been designated as an EF4 category storm, but that could change. The damage is hugely extensive and the total loss of life and property won't be determined for a several days to come as workers dig through the rubble and debris. The above time-lapse video shows how the twister started fairly small then quickly grew into a super-destructive force of nature with wind speeds estimated - so far - to have been upwards to 200 miles per hour. The same region around Oklahoma City was ravaged by an EF5 tornado back in May of 1999. A local meteorologist called today's tornado "the worst tornado in the history of the world." The devastation seen in the aftermath of today's monster tornado lends some credence to that statement but time will tell.

Go to Smithsonian.com to put this deadly storm in perspective.

I feel like there should be some whacky music or pun-filled intro a la America's Funniest Videos, but we'll let this video just stand on its own.

One of the biggest weather events in years has been going on in relative anonymity over the past few days. Cyclone Felleng has been churning over the open waters of the Indian Ocean generating winds of up to 100 mph. Click here to learn more and see some dramatic satellite images of Felleng.

Oct
30
2012

Sandy seen from space: This satellite photo shows the enormity of Sandy as she slammed into the east coast of the United States.
Sandy seen from space: This satellite photo shows the enormity of Sandy as she slammed into the east coast of the United States.Courtesy NASA
I'm always skeptical about storms that get a catchy nickname before they strike. The hype always seems to be more than the outcome. But Sandy (aka Frankenstorm) seems to be living up to her billing. After coming ashore the New Jersey/New York area early Monday evening, her path of destruction is wide and intense. As of noontime Tuesday, the fatality toll had risen to 33 people.

Here's a round up of news sources reporting the impact of this major storm.

Converging factors – A nice recap of the meteorological conditions that combined to make this storm so strong.

The pre-storm view from crew members aboard the International Space Station.

Slide show of photos from damage in the New York City area.

Slide show of photos of damage up and down the eastern seaboard.

Sandy vs. 'The Perfect Storm' – Minnesota-based meteorologist Paul Douglas offered this comparison between Sandy and the infamous "Perfect Storm" that struck in 1991:

In some ways, Sandy will be much like "The Perfect Storm" of 1991, when the remnants of Hurricane Grace interacted with a cold front that moved through the Northeast. As tropical system (strengthened by the warm ocean waters) merged with the cold front, it became more of an typical Mid-Latitude Cyclone (strengthened by the large temperature difference across the front). Interestingly, the center of the storm (minimum central pressure of 972mb) stayed off shore and caused massive damage (estimated to over 200 million dollars with 13 dead). This storm (hybrid Sandy) is expected to MAKE landfall; some models forecasting the central pressure down near 950mb, much lower than that of 1991. You can read more of his insights on Sandy here.

In Chicago today, big waves – Sandy's stretching into the midwest, picking up 20-foot waves on Lake Michigan in Chicago.

Expanded reporting of the final hours of the HMS Bounty – the replica of a historic tall ship which sank off the coast of North Carolina Monday.

Top 10 rejected storm names – and on a lighter note, Dave Letterman goes low-tech to share rejected names for this super storm.