Stories tagged geological forces

UPDATE: Here's an updated video showing the terrifying force of the tsunami that swept across the Japanese city of Sendai. It's not just an unstoppable wave; it's a juggernaut of debris.

8.9 magnitude earthquake hits Japan
8.9 magnitude earthquake hits JapanCourtesy USGS
A monster earthquake hit northern Japan today at 2:46pm local time (11:46pm CST) causing tremendous damage including the triggering of a deadly and devastating tsunami. The images of destruction coming out of the country are both stunning and heartbreaking. Early reports say a 30-foot wave slammed into the city of Sendai washing away houses, cars and other debris – some of it in flames. The city is located about 80 miles from the quake’s epicenter and has a population of over 1 million people. According to the USGS Earthquake site the tremblor occurred at a depth of about 15 miles. The initial shaking is reported to have lasted two minutes, and has been followed by several strong aftershocks. It’s the most powerful quake to hit Japan in 140 years, and there are already reports of 200-300 deaths. But unfortunately that will more than likely rise as time goes on and reports are updated. Tsunami warnings have been issued across much of the Pacific Rim and also Russia. Seven foot waves have already hit Hawaii.

NOAA's Tsunami Warning Center
USGS Earthquake center

While browsing through some recent science stories, I came across this article about a gigantic boulder unleashed by the unpronounceable Icelandic volcano Eyjafjallajokull that erupted earlier this year. The rock stands over 50 feet tall and is estimated to weigh about 1000 tons! That is one big chunk of stone! There's a photo of it, with an explanation of how the impressive boulder came to rest where the photographer shot it.

Previous Buzz post about Eyjafjallajokull
And another previous Buzz post about Eyjafjallajokull

Apr
15
2010

Moving water is an extremely powerful and earth-shaping force of nature. It can also be quite lethal. According to NOAA, over a 30-year average (1979-2008) flash floods have killed more people than any other weather-related natural disaster in the US. With that in mind, here are two remarkable video clips of flash floods that came to my attention via Rebecca Hunt-Foster’s Dinochick Blog. The videos were shot by David Rankin of Rankinstudio.com who keeps close watch on the local weather in southern Utah, and whenever heavy rains occur, runs out with camera in hand to capture the amazing power and erosion of the resultant flash floods, that drag along everything that gets in their way. This explanation of the phenomenon and why it interests him is from his website:

“1 inch of rain over 1 square mile amounts to over 17.38 million gallons of water that need to be drained. Some of the floods in these videos were produced when 2 - 4 inches of rain fell over 30 - 60 square miles, over a few billion gallons of water draining down one wash in the desert. These washes are usually bone dry for most of the year until the monsoon rains come. They can turn into raging torrents within minutes and are very dangerous during this time of year. If there hasn't been much local heavy downpour the floods come through looking like a tsunami with a wall of water that can get up to 5 feet high, and tear up everything in its way. This is what you see happening in these videos. I am also interested in raising awareness when it comes to these beasts. They are quite dangerous, and can come through up to 6 hours after the storms that create them pass by with almost no warning.” – David Rankin

The Mediterranean Sea at dawn
The Mediterranean Sea at dawnCourtesy g.naharro via Flickr
During the late Miocene epoch, waters in the Mediterranean basin evaporated and disappeared several times in what’s termed the Messinian salinity crisis. But at the beginning of the Pliocene epoch, the basin refilled again during an event called the Zanclean Flood. Using drill-hole data and computer modeling, scientists in Europe now have a better understanding of how that event took place, and how it may have only taken a couple of years to refill the entire basin. The research appears in the current issue of the journal Nature.

SOURCE
BBC report

Jun
07
2008

Chinese earthquake location
Chinese earthquake locationCourtesy USGS
The Tangjiashan “quake lake”
formed by a landslide during China’s devastating May 12th earthquake is draining slowly thanks to a sluice constructed by engineers there. Fears of the lake bursting from its earthen dam pushed authorities to find a quick and effective way to release the pressure building from the backed-up water. More than a million people living in the area were under threat of being inundated with millions of cubic meters of water.

As work crews start construction of a second drainage channel, engineers are closely watching downstream riverbanks and bridges for any sign of stress from the surging waters.

The 7.9 magnitude earthquake killed over 60,000 people and more than 17,000 are still missing.

SOURCES AND LINKS
AP story
BBC report
Maps and photos of lake region

Geological processes don't always occur over long stretches of time. Landslides triggered by recent 7.9 magnitude earthquake in China have blocked rivers causing new - and perhaps unstable - lakes to form in the devastated landscape.

Satellite photos taken of the region around Beichuan County show formation of a lake in one of the worst hit areas. Twenty other lakes have formed in Beichuan because of the massive tremor and are being monitored closely according to a story in Chinese Daily.

Death estimates are nearing 60,000, and the quake is thought to have destroyed more than 5 million buildings.

Jun
21
2007

Here today, gone tomorrow: Undated photo combination showing five acre lake that disappeared mysteriously in the southernmost region of Magallanes, Chile. Photo credit: CONAF
Here today, gone tomorrow: Undated photo combination showing five acre lake that disappeared mysteriously in the southernmost region of Magallanes, Chile. Photo credit: CONAF
A glacial lake in Chile has suddenly disappeared according to park rangers at Bernardo O’Higgins National Park in the southern Andes.

“In March we patrolled the area and everything was normal,” said Juan Jose Romero from CONAF Chile’s National Forestry Corporation. “We went again in May and to our surprise we found that the lake had completely disappeared. All that was left were chunks of ice and an enormous fissure.”

The fissure could mean an earthquake may be responsible for the disappearance, since the Magallanes region is known to experience lots of tremors, but the problem is there haven’t been any quakes recently in the park.

“No one knows what happened,” Romero said.

However, an earthquake hasn’t been completely ruled out as the cause. A recent quake in nearby Aysen last April could be the culprit. According to glacial specialist, Andres Rivera, the Magallenes area has seen interesting changes in the last few decades. He noted that the lake didn’t exist 30 years ago.

When the lake was there, it covered about 5 acres, (330 ft by 660 ft) and was about 100 feet deep. It’s not a huge lake, but it’s no backyard fish pond either. Here’s a link that will give you a better idea just how large an area 5 acres is.

Geologists and other experts are heading to the area 1250 miles south of Santiago to investigate so maybe they’ll come up with some answers.

In geological terms lakes are considered ephemeral events, and sometimes changes in the landscape happen gradually, sometimes they happen quite rapidly. This is a good example of the latter.

STORY LINKS

BBC Website Story
OttawaCitizen.com Story (Neat photo)
More on Bernardo O'Higgins National Park