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Loosely Knit : 2 March, 2010

by kenlo on March 2, 2010

http://www.flickr.com/photos/kaet44/1445087954/

1. photo of Ilulissat Icebergs, Disko Bay, Greenland (Flickr/CC photo by kaet44)

Every year, 20 billion tonnes of icebergs calve off the Jakobshavn Isbræ glacier and pass through the Ilulissat Icefjord.

2. Understanding deep ocean circulation and climate modeling

If you follow the latitude lines from much of Europe westward across the Atlantic, you tend to run into Canada. Even if you go to the southern tip of Spain, you’re not much further south than the Virginias. Canada, of course, has a reputation for being rather frozen and inhospitable, while Europe goes to pieces if it snows for more than an hour or two. The difference is mainly due to ocean currents.

At the north edge of the Atlantic Ocean, warm surface water cools off and sinks, drawing in more warm surface water from the south, generating a warm surface current along Europe’s Atlantic coast. Portions of this current comes in from the tropics near Africa and South America, and more is drawn in from the Indian and Pacific Oceans. In addition to making Europe a pleasant place to live, this current also provides the main source of ocean mixing—that is, these currents act to cool the ocean surface temperatures and heat the deep ocean.

More on thermohaline circulation, also known as the “ocean conveyor belt.”

See also:Freak Current Takes Gulf Stream to Greenland

Artic Tern Migration, map courtesy of Carsten Egevang

3. World’s Longest Migration Found–2X Longer Than Thought

Miniature new transmitters recently revealed that the 4-ounce (113-gram) [arctic tern] follows zigzagging routes between Greenland and Antarctica each year. In the process, the arctic tern racks up about 44,000 frequent flier miles (71,000 kilometers)—edging out its archrival, the sooty shearwater, by roughly 4,000 miles (6,440 kilometers).
Photo: Carsten Egevang/ARC-PIC.COM
Since the birds often live 30 years or more, the researchers estimate that, over its lifetime, an arctic tern migrates about 1.5 million miles (2.4 million kilometers)—equal to three trips to the moon and back.

See also: The Arctic Tern Migration Project

Bird of the Sun, a beautiful photographic tribute to the arctic tern by Carsten Egevang

Map of global shipping routes by Bernd Blasius

4. A Year of Global Shipping Routes Mapped by GPS

Scientists have come up with the first comprehensive map of global shipping routes based on actual itineraries. The team pieced together a year’s worth of travel itineraries from 16,693 cargo ships using data from LLoyd’s Register Fairplay and the Automatic Identification System, which tracks vessels using a VHF receiver and GPS.

A few hot spots logged the majority of journeys. The busiest port was the Panama Canal, followed by the Suez Canal and Shanghai.

5. The Mariana Trench to scale

Click on the link for an amazing graphic of the deepest point in the ocean.

via kottke:  “representation of how deep the Mariana Trench is. Turns out it’s really, really, really, really, really, really, really, really, really, really, really, really, really deep.”

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Here come the floods

by kenlo on February 25, 2010

http://www.flickr.com/photos/usgeologicalsurvey/2593475733/

CC/Flickr image: USGS

The first flood of the season arrived early in Natchez, Mississippi.

Meteorologists at the Lower Mississippi River Forecast Center of the National Weather Service had been tracking late January rainfall (“high-water events”) upstream in the Mississippi River Basin.

On Jan 21, the Tennessee River Valley got 1-2 inches of rain, on Jan. 22 the Ohio River Valley received 1.5 inches, on Jan. 24 1.5 inches fell over the Missouri River Valley and on Jan. 25 the Tennessee River Valley received another 1.5-3 inches of rain.

Under “normal” conditions, the Mississippi doesn’t rise significantly until March, as snow melt and other precipitation starts flowing down the river. Even prior to this early precipitation, autumn had dumped substantial rainfall on the Midwest (“the wettest October ever in St. Louis”). As a result, water tables are already high. Spring rain on top of a saturated ground equals more flooding.

Communities along rivers in the Midwest are bracing for would could be a whopper of a spring flood season, with the National Weather Service warning of a “high probability” of significant flooding along parts of the Mississippi and Missouri rivers and their tributaries.

Big Watershed

The Mississippi River Basin is remarkably vast, drawing water from 31 states and two Canadian provinces and covering 40% of the continental United States. Water takes approximately three months to flow from the headwaters at Lake Itasca, Minnesota, to the Gulf of Mexico. Imagine the rain and snow melt shedding off this broad landscape, collecting in the capillaries of streams, merging into rivers, and amassing into the slow wave that rolls down the Mississippi. On the Lower Mississippi, forecasters can see a flood building a long way upstream.

On February 8, the Mississippi reached flood stage at Natchez. While the crest of the flood has already passed New Orleans, flood stage waters continue in some areas between Natchez and Baton Rouge. As the river remained above the 48-foot natural riverbanks this past weekend, crews in Natchez keep a close eye on “sand boils” that form as water displaces soil under the city’s levees. Sandbagging around these boils is part of the seasonal fight against floods. When the river subsides, the crews will wait for the next rise later this spring.

A report from the U.S. Global Change Research Program predicted for the Midwest:

“an increase in precipitation in winter and spring, more heavy downpours, and greater evaporation in summer, leading to more periods of both floods and water deficits.” More “droughts, floods and other extreme events,” in other words.

The flood of media

While the weather is a topic of daily chatter pretty much everywhere, I suppose most people in the U.S. pay little attention to river levels these days. “How’s the hydrological cycle?” rarely comes up in polite conversation. Rivers (and the seas) aren’t as central to most people’s livelihoods or for commerce and transportation as they once were — even though 500 million tons of commercial traffic continues to move on the Mississippi each year.

As spring nears and so does the snow melt, media coverage of Midwestern floods is beginning to appear.

Floods tend to be treated by the media as isolated — and dramatic — news stories. Throughout the year, some part of the world is likely to be passing through its rainy season. So flood stories are not hard to find.

Recent headlines from around the world:
Lusaka
: Eight people die in heavy Zambian floods due to poor drainage
Afghanistan: Afghan floods, avalanches kill 20
São Paulo: Living with the floods
Cumbria, Ireland: The extreme floods in Cumbria
Madeira, Portugal: Madeira floods kill 42, divers hunt for missing

http://www.flickr.com/photos/ricephotos/3967552235

Typhoon Ondoy; CC/Flickr image by IRRI Images

Treehugger recently posted this slide show on the destructive power of floods. The media coverage of the “Snowpocalypse” on the East Coast may transform into news of floods. And, alas, flood stories will become part of the saga in post-quake Haiti, especially when hurricane season arrives.

“Natural” disasters

Floods undoubtedly unleash tremendous pain and suffering around the world, wreaking havoc on the assumed stability of human social and economic affairs. What makes a flood a “natural disaster” — and a headline — is the presence of humans. The combination of human population growth, the expansion of settlements along rivers and coastlines, and increasing threats from climate destabilization will certainly mean more floods:

Droughts and floods account for more than half of the world’s total deaths from disasters, according to the United Nations. But unlike many other catastrophes, most water crises are man-made. Nature may bring the occasional monsoon downpour or dry spell, but environmentalists agree that global warming, dams, deforestation and slash-and-burn farming exponentially exacerbate these seasonal weather patterns.

Sea-level rise, storm surge, and extreme weather events will all contribute to coastal and riverine flooding. In many parts of the world, sewage, toxic runoff, and water-borne disease, like cholera, extend the impact of floods. Inevitably, the most vulnerable communities bear the burden of these disasters. In the U.S., of course, the disproportionate burden of Hurricane Katrina on the poorest residents of New Orleans remains the most visible example.

A flood, in a way, poses a variation on the old question, “If a tree falls in the woods and no one is there to hear it, does it make a sound?” Is it a media story? Flood and flooding are often used interchangeably. Perhaps there’s a distinction between a “flood” and “flooding.” A “flood” represents a condition or an event. “Flooding” is both a local phenomenon and a process, part of the temporal ebb and flow of ecosystems, the timeless hydrological cycles under which landscapes and other species have evolved.

Channeling the river

Since the late 1800s, the Mississippi River Commission has focused on improving navigation and flood control on the lower Mississippi. In 1928, the MRC launched the Mississippi River and Tributaries project, one of the world’s most extensive engineering projects, led by the Army Corps of Engineers.

In order to maintain “order,” much of the Upper and Lower Mississippi River has been dramatically channeled with levees and reservoirs and locks, in the process destroying wetlands and altering the flow of water and sediment. The Mississippi River Delta is in terrible shape. In the state of Missouri, the river now has less than one-fifth of the original wetlands. According to Ana Barros, a civil and environmental engineer at Penn State,

A channel has no capacity to adapt to variable conditions. Tamed, constricted, “It can’t evolve to prepare itself for the next event. This river has nowhere to go.”

For Barros, part of understanding the river is learning to respect it: recognizing that ultimately it will not be controlled. “We must learn to work with the river instead of against it.” This means recognizing the river as a complex, self-regulating system, and seeking to restore as much of its integrity as possible. At the same time, she says, “We have to anticipate the worst, and design systems that work well in failure.”

River restoration is a critical and growing field. Reconnecting the river and floodplains will help to reduce flooding. Even the Corps has begun to integrate conservation biology principles. But the field also needs more coordination and will have to evolve as our understanding of climate change and river ecosystems deepens.

Learning to work with the natural systems will also inevitably force significant tradeoffs. Along the Mississippi, agriculture and urban centers have expanded in conjunction with the channelization of the river. Reintegration of natural buffer areas will place constraints on the location of development along the river. Commercial traffic on inland waterways will also have to adapt. But this is a long-term process of necessary rethinking and restoration.

Ultimately, this restoration involves shifting the focus from “floods” to “flooding.” As Ana Barros suggests, we will have to learn to respect the river. We can also reacquaint ourselves with and embrace the pattern of the river:

Rivers pulse in reflection of the seasons. When there is snowmelt and during rainy seasons, the total volume of water in the river increases.  As water in the river channel rises, islands and riverbanks that are usually exposed are submerged. Increased levels of water scour the land it flows over and increases the amount of sediment carried with the current.  The process is reversed in the dry season. Land that was submerged is exposed, less water and slower current allow particles to settle out of the water and be deposited on the riverbed itself. Year after year this cycle is repeated.

Thanks to @River_Restore, @NEMWIUpperMiss, @DDimick, @troutheadwaters

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Loosely Knit : 16 February, 2010

February 16, 2010

A collection of loosely-knit links. Not about blackbirds.
1. blackbird
Flickr CC image by Striatic (Bryan Partington)
2. Pale Blue Dot: An Alien View of Earth
Twenty years ago last week, NASA’s Voyager 1 sent back this photo from four billion miles away. From NPR.
“It was just a little dot, about two pixels big, three big,” [Candace Hansen-Koharchek] says. [...]

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Looseleaf : 15 February, 2010

February 15, 2010

A collection of loosely-knit links.
1. The Grid, Our Cars and the Net: One Idea to Link Them All

From Wired last year:
Robin Chase considers the future of electricity, the future of cars and the internet three terms in a single equation, even if most of us don’t yet realize they’re on the same chalkboard. Solve the [...]

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City of (Lost) Streams

February 8, 2010

Where there is life, there is water. Water finds its way across a terrain. It shapes the land and connects places within a landscape. Human settlements inevitably begin around water: oceans, rivers, streams, springs, wells, aqueducts.
Where there are people, the landscape changes in unique ways.  As cities grow — and as urbanization spreads — cities [...]

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Five ways of looking at the U.S.

February 1, 2010

Here are five maps I came across during the last few weeks.
They involve high-speed passenger rail; a re-imagined map for the U.S. electoral college; landscape conservation; North American migration flyways; and wildlife “megalinkages.” The images are accompanied by minimal commentary, mainly their source info.
I’ll leave it to you to make any connections. Your thoughts and [...]

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On the wing with whooping cranes and Operation Migration

January 28, 2010

Last week, 20 young whooping cranes completed their first migration led by their mentors in flight, ultralight aircraft flown by pilots from Operation Migration. The 89-day, 1285-mile (km) journey started at the Necedah National Wildlife Refuge in Wisconsin and traversed seven states, until the cranes reached their destinations at the St. Marks and Chassahowitzka NWRs [...]

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What are Landscape Conservation Cooperatives?

January 16, 2010

“…climate change does not respect juridictional boundaries.”
– Hector Galbraith, Director – Climate Change Initiative, Manomet Center for Conservation Studies
Of course, no sooner do I post about colleges and universities collaborating at the bioregional level than I come across this exciting initiative from the U.S. Fish and Wildlife Service: landscape conservation cooperatives.
From the Service’s FAQ sheet:
What [...]

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Connecting Colleges by “Nature States”: public universities for the 21st Century (part 1)

January 14, 2010

“All education is environmental education.”
– David W. Orr
It’s time to update the mission of U.S. land-grant and state universities to align education and research with a growing understanding of ecosystems and the world’s changing environmental and social conditions. That means working together across landscapes and bioregions. We need colleges connected by nature.
In the last post, [...]

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The Green Campus and Beyond: from bowl games to bioregions?

January 8, 2010

The start of winter and the new year bring many things: Christmas bird counts, whale migration along the Pacific Coast, New Year’s resolutions, and…college football bowl games (U.S. colleges, U.S. football).
Ah, you say, that last one makes you…a) giddy, b) annoyed, c) like, whatever. (I get a thrill out of watching college football, but don’t [...]

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