Stories tagged natural disaster

Iceland may be the Rodney Dangerfield of Europe – it just doesn't get no respect – but geologically it's at the epicenter of world attention these days. Iceland is in a volcano hot zone and an eruption Sunday of the volcano Eyjafjallajokull has garnered a lot of attention. Historically, every time Eyjafjallajokull erupts, the larger volcano Katla erupts soon after.

Below is aerial video shot by the Iceland Coast Guard showing Sunday's eruption. Stay tuned to see if there are more eruptions to come. Past eruptions of Katla, with lava and gases passing through Iceland's ice sheets, have created toxic smog that have damaged crops and sickened people in the British Isles. Here's the full AP report.

Mar
18
2010

For hundreds of years, thousands of people have connected with the Mississippi River. Today, we sometimes forget that the Mississippi is always flowing through our fair cities, at least until it floods.

In this moment, the river can be an extraordinarily humanizing resource. When we stand together on the Science Museum's plaza, peek over the rails on Kellogg Blvd.'s parkland, or sit near the steps on Harriet Island, all gazing at the flooding river, we are not accountants, scientists, or novelists but everyday people witnessing an event that still produces the same awe, fear, romance, or dread that thousands of people for hundreds of years before us have experienced when they too watched or experienced a flood.

In future posts, my colleagues and I will chat about the impact of flooding on the Mississippi's landscape and try providing some historical perspectives on river floods.

If you'd like to learn more about our National Park Service unit, the Mississippi National River and Recreation Area, please visit us at www.nps.gov/miss.

-Ranger Brian

Check out our full feature on the 2010 Mississippi River flooding.

Mar
17
2010

Look out the window or walk down the street to nearly any river or stream in Minnesota right now and you are likely to observe two things about the river:

  1. it is getting deeper (or “rising” in relation to the banks); and
  2. it appears to be moving faster.

You can, of course, confirm these observations by investigating reports from gauging stations along these rivers, maintained by the U.S. Geological Survey. (See data for the gauging station serving downtown St. Paul.) But what is really happening?

It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.
It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.Courtesy Liza Pryor

Until a river flows over its banks, it is considered to be in a “bankfull” state. In this state, the water flowing through the river is confined to a relatively fixed channel area. Simply put, floods occur because more water is being introduced into this channel from upstream, due to snowmelt, heavy rains, or a dam breach. As this added volume of water moves through a fixed area, it both increases in velocity and in depth until it overflows the banks, at which point some, but not necessarily a lot, of the volume and velocity moving through the channel are reduced.

Scientists call the rate of flow through a channel “discharge." Discharge is defined as the volume of water passing through a given cross-section of the river channel within a specified period of time.A simple equation for determining discharge is

Q = D x W x V

where Q = discharge, D = channel depth, W = channel width and V = velocity.

Looking at this equation, it is easy to see that if discharge becomes greater and channel width is fixed, then an increase in both volume and depth (or height relative to the banks) is likely to be the cause. Discharge can be measured in cubic feet per second or cubic meters per second, for example.

But is the river flowing at the same rate at the surface as it does along its banks and beds? Understanding this requires investigating some more detailed equations, as the banks and bed introduce friction, which affects the rate of flow.

To learn more about rivers and how they flow, you may want to check out the works of Luna Leopold, and M. Gordon Wolman. In particular:

  • Leopold, Luna B. (2006, reprint). A View of the River. Harvard University Press; and
  • Leopold, Luna B.; Wolman, M. Gordon; and Miller, John P. (1995). Fluvial Processes in Geomorphology. Dover Publications, both classics for understanding how rivers work.

Also, check out our full feature on the 2010 Mississippi River flooding.

Mar
17
2010

As of 11:19am, the US Geological Survey is forecasting that the Mississippi River will crest here in downtown St. Paul at 18 feet.

New flood crest prediction, 3/17
New flood crest prediction, 3/17Courtesy USGS

That would put Water Street and the lower section of Lilydale Regional Park underwater (at 14'), require secondary flood walls at the St. Paul Downtown Airport (17'), submerge much of Harriet Island (17.5'), and make Warner Road impassable due to high water.

An 18-foot crest would also make this year's flood #9, historically speaking, bumping the flood of 1986 (16.10') off the top-10 list.

Also, check out our full feature on the 2010 Mississippi River flooding.

Mar
16
2010

All day, up in the Mississippi River Gallery, people have been stopping to look out the window and watch the river.

Here's how the US Geological Survey sees it:
Mississippi River, actual vs. forecast, 3/16/10, 1pm
Mississippi River, actual vs. forecast, 3/16/10, 1pmCourtesy USGS

The river's rising, but not as fast as yesterday. And yesterday's rise outpaced predictions by almost a foot, but today the rise matches the predicted curve almost exactly.

So what are folks seeing out the window? Take a look.

Also check out our full feature on the 2010 Mississippi River flooding.

Watch the steps: They're a good benchmark.
Watch the steps: They're a good benchmark.Courtesy Liza Pryor

Raspberry Island: Still high and dry
Raspberry Island: Still high and dryCourtesy Liza Pryor

Looking upstream: You're still looking at Harriet Island. But low-lying areas of Lilydale (upstream, south side of the river) get inundated when the river reaches 14 feet or so. Right now, that's predicted to happen sometime after 7pm on Sunday, 3/21.
Looking upstream: You're still looking at Harriet Island. But low-lying areas of Lilydale (upstream, south side of the river) get inundated when the river reaches 14 feet or so. Right now, that's predicted to happen sometime after 7pm on Sunday, 3/21.Courtesy Liza Pryor

While much of the Pacific Rim area was on a tsunami alert this weekend in the wake of the earthquake in Chile, the harbor of Long Beach experienced something much different on Saturday. The harbor had a huge tidal drop occur in just a matter of minutes, grounding many sailboats and yachts and closing the harbor to large sea vessels for a while. Here's a complete video report:

The other amazing thing, nothing anywhere near this drastic happened in any other California harbors the same day.

It's been a very snowy winter so it should come as no surprise that the flood risks in Minnesota are going to be high as well. There's a 60-percent chance that the Mississippi River will be creeping up close to our backdoor here at the museum in the latest forecast announced today. Start packing the sandbags right now in Moorhead and Fargo. There's a 98-percent chance that the Red River will flood this spring.

Check out the Science Buzz 2010 flood feature now.

Dec
04
2009

Another young scientist: Desperately trying to get his research noticed. But it may already be too late.
Another young scientist: Desperately trying to get his research noticed. But it may already be too late.Courtesy Rrrrred
Hey, Buzzketeers. I’m going to be straight with you up front (I always am):

I haven’t actually seen “The Day After Tomorrow,” even though it will feature prominently in this post. I did see the preview, however, and I know the title, so I’m confident that I can sum the film up pretty accurately.

The is how The Day After Tomorrow goes, more or less:

The kid from Spiderman, Peter Parker, is a young scientist trying to make a name for himself in the big city. He has a crippling fear of wolves. Trying to be a famous scientist, however, is a lot like trying to be a Hollywood celebrity: there are a million other kids out there just like you, except that some of them are better looking with bigger muscles, or more feminine ankles, so you have to be willing to act a little crazy, or go on camera naked.

Peter Parker, fortunately, opts for the “act a little crazy” route. He soaks up a couple red bull-vodkas and starts researching. After 7 panicked days and 6 insane nights, Peter says, “Check it out! The Day After Tomorrow, the poop is really going to hit the fan!” But the scientific community was all, “Whatever, Parker. Take that shirt off, and let’s get you on camera.” They were so preoccupied with the thought of Peter’s scientist muscles that they failed to realize that he was right! Like two sick bears squatting on an airboat, the poop was really about to hit the fan.

Sure enough, Peter Parker’s discovery proved to be accurate. The planet’s ocean currents went all haywire, and a couple days later things got really cold and stupid. Peter Parker, despite being shirtless at this point, was more prepared for the situation than everyone else, and he grabbed a sled and went to rescue a friend of his, possibly a beautiful woman or man, who was trapped in an elevator behind some very impressive icicles. Along the way, Peter had to avoid the many wolves that immediately moved into the frozen cities in search of delicious, un-canned human food, but once he rescued his beautiful friend the wolves could no longer be dodged. After a 45-minute-long wolf-fighting scene, Peter emerged bloody and victorious. He had truly conquered this world of the day after tomorrow!

It’s a little silly isn’t it? I mean, everyone knows that ocean currents are vital for spreading heat across the planet, and moderating higher latitude climates. Duh. Surface water is warmed in the tropics, and is pushed into currents by regular wind patterns and the rotation of the Earth. As it reaches colder seas, the water releases heat and moisture into the atmosphere. Colder and saltier now (because the salt in water doesn’t evaporate), the water is denser, and it sinks down to join deeper currents, where it will flow thousands of miles around the planet, before eventually returning to the tropics to be warmed again. Tada. And, of course, shortly after the end of the last ice age, a huge, cold, freshwater glacial lake burst its shores and spilled into the north Atlantic, halting this water cycle and disrupting the Gulf Stream current to plunge the Earth into another thousand years of coldness. But that sort of thing couldn’t happen the day after tomorrow, could it? Noooo. We all know that. It would take years for such a tremendous change in climate to occur. What a silly movie.

Or… maybe not. A new study from the University of Saskatchewan suggests that the story of Peter and the Wolves may not be as far fetched as we all thought. Based on lake core samples, the research seems to indicate that the drastic cooling, at least in Europe, could have occurred over a period as short as just a few weeks, not over the space of years, as was previously accepted.

Lake cores are samples of the deep mud and sediment at the bottoms of lakes, and they’re surprisingly useful for telling what happened above a lake a long time ago. Think about it—if things got really windy, for example, lots of dust and dirt would be blown onto the lake, and it would eventually settle down to the bottom, forming a unique layer. Or if all the plants nearby died suddenly, you’d probably see less pollen in the layer deposited at that time. Scientists can even look at the isotopes of the atoms in lake core layers to learn about what was happening at the time—carbon isotopes can show how much stuff was alive in the lake, and oxygen isotopes can indicate local temperature and rainfall. Examining cores from a very old lake in Ireland, the researchers discovered that the transition to the Younger Dryas period (the sudden return to ice age-like conditions) happened very suddenly, perhaps in as short a time as a month. Peter Parker was right! Peter Parker was right!

As I understand it, though, this rapid and severe change hinges on the North Atlantic Current (the Gulf Stream) being totally shut down very quickly. Cold fresh water released by melting icecaps could very likely affect weather patterns, but something on this scale would require a fairly catastrophic event—some scientists suggest that the Younger Dryas could have been triggered by some sort of extra-terrestrial impact, although the theory is heavily debated.

Still, if some hot young scientist approaches you with some hot young ideas, don’t immediately insist that he take his shirt off—he might be saying something worthwhile