Posts Tagged ‘Mississippi River’

Why You Should Pay Attention to East Coast Quakes: A Monster is Stalking the Heartlands

August 25th, 2011 08:27 admin View Comments

For the Central US, it’s a matter of when, not if.

The magnitude 5.8 quake that struck central Virginia on Tuesday was felt from Florida to Maine to Missouri. “This is probably the most widely felt quake in American history, even though it was less than a 6.0,†says Michael Blanpied, a USGS seismologist DISCOVER contacted after the event. The reason for this intensity is that the East Coast, like the controversial New Madrid Seismic Zone in the central U.S., is located amidst old faults and cold rocks in the middle of the North American tectonic plate, and seismic waves travel disturbingly far in such stiff, cold rock.

We would do well to take a hint from Tuesday’s expansive shake-up. It’s lucky that it struck in rural America. But a similar tremblor in the crowded cities of the central U.S. above the New Madrid zone is a matter of when, not if. And the region is woefully unprepared to mitigate the damage, as Amy Barth explores in a piece from an upcoming issue of DISCOVER:

The disastrous winter of 1811–12 is the stuff of legend in the Midwest. In the span of a few months, three major earthquakes rocked Missouri, Tennessee, and Arkansas, violently shaking 230,000 square miles stretching from St. Louis to Memphis. Witnesses claimed that the ground rolled in waves several feet high and the Mississippi River flowed backward. Some reports described buckling sidewalks in Charleston, South Carolina, and tremors that reached as far as Quebec. Had seismographs been available at the time, scientists believe those tremors would have registered magnitudes at least as great as the 7.0 quake that devastated Haiti in 2010 and possibly as high as 8.0. These would place them among the worst in U.S. history.

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Source: Why You Should Pay Attention to East Coast Quakes: A Monster is Stalking the Heartlands

Five Years Later, Could New Orleans Withstand Another Major Hurricane?

August 30th, 2010 08:07 admin View Comments

Hurricane_Katrina_FloodingThe city of New Orleans’ defenses are certainly better than they were five years ago, when Hurricane Katrina breached the levees and flooded the city. With the five-year anniversary of that disaster upon us, however, the question that hangs in the air is: Would those refurbished barriers stand up to another Katrina, or something worse?

Better Barricades

In the last five years, the federal government has invested about $15 billion to revamp the New Orleans levee system.

This time, tougher foundation material like a mixture of construction clay and cement, is being used in the soil to hold structural sections of wall designed as an inverted T instead of their previous I-shape. The new design is considered stronger, allowing steel pillars to bracket each end into the ground. Total completion is expected in June 2011. [Christian Science Monitor]

The levee system stretches about 350 miles around the city, and its walls stand about 30 feet high (Katrina’s storm surge rose to about 28 feet).

Bigger Storms?

Gregory Gunter of the U.S. Army Corps of Engineers trumpets the new systems as a defense against the so-called “100-year storm”—a tempest so bad it has only a 1 percent chance of striking in a given year.

The system shouldn’t fail in a “400-year” Katrina-strength storm either, although Gunter says such a surge would probably flow over the barriers. This would lead to some flooding, but nothing like the scale of Katrina, which pushed over walls and breached levees. [New Scientist]

However, flood experts point out, the people who really know about keeping flood waters at bay—the Dutch—build their levees with a much larger investment, intending them to withstand a “10,000-year” event. In addition, because our hurricane records go back only so far, and because the past may not be an accurate picture of future storms, those year designations may be misleading anyway.

Paul Kemp, director of the National Audubon Society’s Louisiana Coastal Initiative in Baton Rouge, and former storm surge modeller, says the new designs presume that future storms will resemble past ones. He points out that climate change may increase hurricane strength. [New Scientist]

Don’t Forget the Wetlands

The Corps of Engineers has taken its share about abuse for Katrina failures (including by New Orleans resident Harry Shearer of The Simpsons and This Is Spinal Tap fame, whose new Katrina documentary is out now). The levees weren’t the only problem, though: New Orleans’ degraded wetlands put the city in added danger.

According to the Army Corps, all of the levees that failed during Katrina lacked wetland protection; the levees with a wetland buffer remained intact. Scientists have estimated that storm surge is diminished by one foot for every square-mile of wetland it travels through [National Geographic].

Now, groups like the Sierra Club are trying to revive the cypress ecosystem that once thrived in the shallow waters, and are doing so with a plan that actually requires pumping in partially treated sewage. With a high enough volume of biosolids—semi-treated sewage—they could add up to four feet of new material in which plants could take root.

The swamp has been killed primarily through saltwater intrusion from the various surrounding canals that connect the Mississippi River to the Gulf of Mexico. A pulse of freshwater sewage could make the site more suitable for wetland species. In return, those species would help filter and clean the effluent [National Geographic].

Unknown Toll

President Obama spoke at Xavier University of Louisiana in New Orleans yesterday to mark the Katrina anniversary, praising the growth of small business and announcing that the federal government was finally ready to dole out its promised $2 billion investment in the city school system. But one thing still remains unsettled: Just how many people we lost, and who they are.

The Houston Chronicle reports that about 500 of the 1,500 people in Louisiana’s recognized death toll remain unidentified. And that official count could be a lowball figure, some argue:

John Mutter, a Columbia University professor, has been gathering personal testimonials and public records of those killed in Katrina for an effort he calls Katrinalist. Mutter estimates the true death toll will top 3,500 if those killed by the storm and by its many after-effects are accurately tallied. And yet other counts put the toll at an estimated 1,800 [Houston Chronicle].

Image: Office of the President of the United States

Source: Five Years Later, Could New Orleans Withstand Another Major Hurricane?

Oil Arrives In Louisiana; Defense Booms Inadequate

May 22nd, 2010 05:20 admin View Comments

eldavojohn writes “People in mainland Louisiana are seeing the beginnings of the oil’s full effects on wildlife in the area. Sticky rust colored oil covers the reeds like a latex paint indicating that the efforts to lay miles of floating booms to keep it away from the fragile marshes are useless. They are experiencing what the Plaquemines (mouth of Mississippi River) saw last week and it now appears that their defenses were inadequate. Only time will tell how much more worse it can get as BP still scrambles for a solution. NPR also ran a story critical of Obama’s ‘scientific approach’ that he promised to use in office and how well it’s being applied and holding up during this crisis.”

Source: Oil Arrives In Louisiana; Defense Booms Inadequate

Gulf Oil Spill: Fisheries Closed, Louisiana Wetlands Now in Jeopardy

May 3rd, 2010 05:23 admin View Comments

NASA Gulf oil Apr 29A week from today the Gulf of Mexico oil spill will still be pouring vast volumes of oil into the water. And that still might not be the end of it. That’s the latest word from the oil company BP, whose efforts to shut off the leak have met with failure so far, and whose new plan will take another week—if it works at all.

BP PLC was preparing a system never tried before at such depths to siphon away the geyser of crude from a blown-out well a mile under Gulf of Mexico waters. However, the plan to lower 74-ton, concrete-and-metal boxes being built to capture the oil and siphon it to a barge waiting at the surface will need at least another six to eight days to get it in place [AP].

There are presently three leaks that were created when the Deepwater Horizon rig exploded and sank into the gulf. BP says today that it still hopes to install a shutoff valve on one of them, but that’s not an option for the others. So the company wants to place one of these “containment domes” on the largest leak in about a week, and then another on the final leak a couple of days after that.

But while BP, with help from the military, struggles to stop the flow, some of the environmental consequences are becoming clear already. Over the weekend, the National Oceanic and Atmospheric Administration announced that fishing would be closed across the Gulf region, from the Mississippi River to the Florida panhandle, for 10 days at least.

The U.S. Gulf coast is a rich breeding ground for fish, crabs, oysters and shrimp and accounts for about 20 percent of the nation’s total commercial seafood production. The shrimp and oyster supply, in particular, is heavily concentrated in the Gulf [Reuters].

In addition, crude is now creeping toward the fragile wetlands of the Gulf Coast, and Louisiana in particular. Due in part to pollution, construction, and natural disasters like hurricanes Katrina and Rita, the marsh lands of the Mississippi delta have shrunk drastically; since the 1930s, Louisiana lost an area the size of Delaware to the sea.

Healthy wetlands would have some natural ability to cope with an oil slick, said Denise Reed, interim director of the Pontchartrain Institute for Environmental Sciences at the University of New Orleans. “The trouble with our marshes is they’re already stressed, they’re already hanging by a fingernail,” she said. It is possible, she said, that the wetlands’ “tolerance for oil has been compromised.” If so, she said, that could be “the straw that broke the camel’s back” [The New York Times].

It would be not only an ecological disaster if the oil influx killed off this ecosystem: Compromised wetlands mean less protection for New Orleans against the storm surge brought by hurricanes.

On the political side, BP’s CEO, Tony Hayward, has said that the company accepts full responsibility for the spill and would pay up for “legitimate” claims of damage caused by the slick. However, the scope of this spill is so vast that the list of damages may stretch on and on. Already last week Louisiana shrimpers filed suit against BP for endangering their livelihood. If the spill indeed destroys ecosystems on the Gulf coast, the courts will probably have to sort out responsibility for that, too.

Our previous posts on the Gulf Oil Spill:
80beats: Gulf Oil Spill Reaches U.S. Coast; New Orleans Reeks of “Pungent Fuel Smell”
80beats: Uh-Oh: Gulf Oil Spill May Be 5 Times Worse Than Previously Thought
80beats: Coast Guard’s New Plan To Contain Gulf Oil Spill: Light It on Fire
80beats: Sunken Oil Rig Now Leaking Crude; Robots Head to the Rescue
80beats: Ships Race To Contain the Gulf of Mexico Oil Spill

Image: NASA

Source: Gulf Oil Spill: Fisheries Closed, Louisiana Wetlands Now in Jeopardy

Could Strobe Lights and “Bubble Curtains” Stop Invasive Asian Carp?

February 12th, 2010 02:21 admin View Comments

asian-carpAsian carp—the giant invasive fish that have been moving up the Mississippi River for the better part of a decade–are getting close to the Great Lakes, and in fact some may have already crossed the barrier. For the lakes’ protectors, this is a near-doomsday scenario: Many fear that the ravenous carp could destroy the ecosystem by gobbling up the food that native fish depend on. This week the White House proposed a plan that would devote nearly $80 million to stopping the fish’s advance, but it’s not pleasing many people around the issue.

On one side, many environmentalists, as well as people who rely on Great Lakes fishing for their livelihood, have called on the federal government to shut down locks that connect the river to Lake Michigan. Michigan Governor Jennifer Granholm says, “The economic damage from these carp coming into the Great Lakes system would be irreparable…. They should shut the locks down until they get these other measures in place, and permanently have a solution to separating these two water systems” [Detroit News]. Granholm and other governors from the region met recently to try to craft another solution after the Supreme Court ruled that Illinois didn’t have to close the locks to stop the carp if it didn’t choose to.

Naturally there’s one group that would be mightily upset at closing the shipping locks: shipping companies. Illinois Rep. Judy Biggert said efforts to close locks and restrict barge and boat traffic in Chicago waterways would damage the local economy and have far-reaching national implications [Detroit Free Press]. The administration’s compromise plan would call for occasional closures of the locks, and though it would only conduct a long-range study of full closure, shipping representatives have still balked at that.

The federal plan is full of bizarre-sounding alternatives to closing the locks, too. Among them: barriers using sound, strobe lights and bubble curtains to repel carp and biological controls to prevent them from reproducing. They’re promising measures – but still on the drawing board [AP]. The plan would also bolster the system of electrical defenses in the water, intended to emit shocks that either scare the carp away or knock them unconscious. But since Asian carp DNA has now been found upstream of those barriers, it seems that at least some fish are slipping through.

The White House is set to brief the public on its plan this afternoon. But while they’re trying to play peacemaker in a money fight between states, they shouldn’t expect a rosy reception from anyone.

Image: U.S. Fish & Wildlife Service

Source: Could Strobe Lights and “Bubble Curtains” Stop Invasive Asian Carp?