Archive for the ‘science’ Category

Antrophogenic transformation of the terrestrial biosphere

Sunday, October 7th, 2012

[Editor’s note: The new “anthropocene” age has been detailed by the likes of The Economist, National Geographic Magazine,  The New York Times, and Wired. While much has been made of miles of road and general interconnected transportation network,  population density, and other measures,  I’m most captivated by this newish map showing “years of intensive use”. Get your Jared Diamond out and study this map. Thanks Hugo! More maps at Ecotope, thanks Andrew!]

Perhaps the most obvious mark we’ve made to the planet is in land-use changes. For millennia, humans have chopped down forests and moved rock and soil for agriculture and pastureland—and more recently, for construction.

Antrophogenic transformation of the terrestrial biosphere

CREDIT: ERLE ELLIS, ADAPTED FROM E. ELLIS, PROCEEDINGS OF THE ROYAL SOCIETY A, 369:1010 (2011) From the Science article “A global perspective on the anthropocene” DOI: 10.1126/science.334.6052.34

Ascension Island: Like Easter Island, Ascension Island has lessons for the planet—cheerful ones (Economist)

Monday, January 3rd, 2011

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[Editor's note: Fun geo writeup of that spot of rock in the Atlantic near St. Helena. Thanks Derek!]

AT THE top of Green Mountain, the central peak of Ascension Island, there is a small pond, dotted with lilies, shadowed to one side by the fronds of a pandan tree. It is the only open body of fresh water on the island—and for a thousand kilometres in any direction. Around Dew Pond grows a grove of towering bamboo, beyond which the trade winds blow incessantly from the south-east. Within the grove the air is still and damp.

Along the trailing ridge of the summit are fig trees, Cape yews and a garland of remarkably vigorous ginger. Below, on the mountain’s lee side, trees and shrubs from all parts of the world spread down the hillside to a landscape of casuarina trees—ironwood, or she-oak—and thorny chaparral around its base. Even on the bleaker windward slope, grasses and sedges are dotted with Bermuda cedar and guava bushes. Above, the bamboo scratching at their bellies, are the clouds the trade winds bring; some days they cover the mountain top.

Once seen as too dry to be worth inhabiting, Ascension Island is becoming greener at an increasing rate. People are responsible. In part, their contribution was unwitting: the thorny mesquite that anchors a lot of the island’s scrub was introduced for a landscaping project just 50 years ago. But the forest on the peak of Green Mountain represents a deliberate attempt to change the island’s climate to make it more habitable. It is the centrepiece of a small but startling ecological transformation which is part experiment and part accident, part metaphor and part inspiration.

Ascension was discovered by the Portuguese in 1501. Just to the west of the mid-ocean ridge that separates South America’s tectonic plate from Africa’s, it is the top of a volcano which rises steeply from abyssal plains more than four kilometres below the surface of the ocean. The volcano made it above that surface only a million or so years ago, since when the island has grown to about 100 square kilometres. Before people arrived it was home to just a flightless bird, a land crab and no more than 30 species of plant, none as big as a bush. It was so barren and isolated that during the following three centuries of assiduous empire-building neither the Portuguese nor any other nation bothered to claim it. When Captain Cook passed by in 1775, Georg Forster—later to become renowned for his accounts of exploration—wrote it off as a “ruinous heap of rocks”, drearier even than Tierra del Fuego and Easter Island. But Forster’s naturalist father Johann saw something more promising:

Continue reading at The Economist . . .

“Joy of Stats” from BBC4 featuring Hans Rosling

Monday, January 3rd, 2011

Now on YouTube! This hour long documentary “takes viewers on a rollercoaster ride through the wonderful world of statistics to explore the remarkable power they have to change our understanding of the world, presented by superstar boffin Professor Hans Rosling, whose eye-opening, mind-expanding and funny online lectures have made him an international internet legend.” BBC4

Exploring Place through User-generated Content: Using Flickr to Describe City Cores (Spatial Info Sci)

Monday, August 9th, 2010

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[Editor’s note: Good focus on vernacular geography, on how we name and describe space, with a particular focus on downtown city cores explored thru millions of photos on Flickr. “Importantly, it deals with regions which are typically not represented in formal administrative gazetteers and which are often considered to be vague.” Never seen Flickr geography before? Check out Aaron’s flickr shapetiles (map), shpfile browser, and geotagger world atlas.]

Republished from the Journal of Spatial Information Science.
By Livia Hollenstein and Ross Purves

Terms used to describe city centers, such as Downtown, are key concepts in everyday or vernacular language. Here, we explore such language by harvesting georeferenced and tagged metadata associated with 8 million Flickr images and thus consider how large numbers of people name city core areas. The nature of errors and imprecision in tagging and georeferencing are quantified, and automatically generated precision measures appear to mirror errors in the positioning of images. Users seek to ascribe appropriate semantics to images, though bulk-uploading and bulk-tagging may introduce bias. Between 0.5–2% of tags associated with georeferenced images analyzed describe city core areas generically, while 70% of all georeferenced images analyzed include specific place name tags, with place names at the granularity of city names being by far the most common. Using Flickr metadata, it is possible not only to describe the use of the term Downtown across the USA, but also to explore the borders of city center neighborhoods at the level of individual cities, whilst accounting for bias by the use of tag profiles.

Continue reading via their PDF . . .

Resolving the iPhone resolution (Discover)

Monday, June 14th, 2010

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[Editor’s note: Good overview of scale (for eyes, and for maps) with remote sensing principles applied to tackle pixel density and the eye’s ability to resolve that resolution. See also post on smart phone screen sensor accuracy. Thanks anonymous twitter user!]

Republished from Discover Magazine.

With much bruhaha, Steve Jobs and Apple revealed the new iPhone 4 yesterday. Among other features, Jobs said it has higher resolution than older models; the pixels are smaller, making the display look smoother. To characterize this, as quoted at Wired.com, he said,

It turns out there’s a magic number right around 300 pixels per inch, that when you hold something around to 10 to 12 inches away from your eyes, is the limit of the human retina to differentiate the pixels.

In other words, at 12 inches from the eye, Jobs claims, the pixels on the new iPhone are so small that they exceed your eye’s ability to detect them. Pictures at that resolution are smooth and continuous, and not pixellated.

However, a display expert has disputed this. Raymond Soneira of DisplayMate Industries, was quoted both in that Wired article and on PC Mag (and other sites as well) saying that the claims by Jobs are something of an exaggeration: “It is reasonably close to being a perfect display, but Steve pushed it a little too far”.

This prompted the Wired article editors to give it the headline “iPhone 4’s ‘Retina’ Display Claims Are False Marketing”. As it happens, I know a thing or two about resolution as well, having spent a few years calibrating a camera on board Hubble. Having looked this over, I disagree with the Wired headline strongly, and mildly disagree with Soneira. Here’s why.

First, let’s look at resolution*. I’ll note there is some math here, but it’s all just multiplying and dividing, and I give the answers in the end. So don’t fret, mathophobes! If you want the answers, just skip down to the conclusion at the bottom. I won’t mind. But you’ll miss all the fun math and science.

Continue reading at Discover Magazine . . .

A New El Niño (National Geographic)

Thursday, March 18th, 2010

[Editor's note: Spoiler alert: "El Niño Modoki (Japanese for “similar but different”) triggers more landfalling storms in the Gulf of Mexico and the western Caribbean than normal, and more tropical storms and hurricanes in the Atlantic than El Niño does. Another difference: Modoki’s precipitation patterns are the reverse of El Niño’s—making the American West, for instance, drier rather than wetter."]

Republished from National Geographic Magazine.

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It used to be simpler. Whenever the surface waters of the equatorial Pacific turned warmer than normal in summer, climatologists would expect an El Niño year, then forecast when and where droughts, floods, and hurricanes might occur. But that was before a study by Georgia Tech scientists, led by Hye-Mi Kim, deciphered the effects of another pattern in which high temperatures are confined to the central Pacific (Click this link to expand the graphic). Now the already difficult field of atmospheric forecasting has become even trickier.

Continue reading at National Geographic Magazine . . .

Conflict conservation: Biodiversity down the barrel of a gun (Economist)

Thursday, March 11th, 2010

[Editor’s note: Featuring the DMZ on the Korean peninsula and Chagos Islands (Diego Garcia) of the Indian Ocean. Both of these features can be found in Natural Earth, the free GIS map of the world.]

Republished from the Economist. Feb 8th 2010

THERE was a time when conservation meant keeping people away from nature. America’s system of national parks, a model for similar set-ups around the world, was based on the idea of limiting human presence to passing visits, rather than permanent habitation.

In recent years this way of doing things has come under suspicion. To fence off large areas of parkland is often impractical and can also be immoral—in that it leads to local people being booted out. These days, the consensus among conservationists is to try to manage nature with humans in situ. But there are still “involuntary parks”, to borrow a phrase from the writer and futurist Bruce Sterling, that serve to illustrate just how spectacularly well nature can do when humans are removed from the equation.

Some such “parks” are accidents of settlement, or its absence. Nature is preserved in those rare places that people just have not got round to overrunning—for example the Foja Mountains in western New Guinea, an area of rainforest that teems with an astonishingly rich variety of plants and animals. Others are accidents of conflict: places from which people have fled and where the fauna and flora have thrived as a result.

Continue reading at the Economist . . .

Climate change’s impact on forests being measured via expanding tree trunks (Wash Post)

Thursday, March 11th, 2010

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[Editor's note: Humorous but scientific take on "tree huggers" in the U.S. mid-Atlantic. Catching up on some old clippings as I roll back into DC.]

Republished from The Washington Post.

By David A. Fahrenthold. Saturday, February 20, 2010

Jess Parker hugs trees.

In the woods of Anne Arundel County, he throws his arms around tulip poplars, oaks and American beeches, and holds them so tightly that his cheek presses into their bark. This is not some hiker on a lark: anybody, hopped up on campfire coffee and exercise endorphins, might hug a tree once.

This is science. Parker has done it about 50,000 times.

Parker, a forest ecologist at the Smithsonian Institution, has spent the past 22 years on a research project so repetitive, so time-consuming, that it impresses even researchers with the patience to count tree rings. Since 1987, he and a group of volunteers have embraced thousands of trees, slipped a tape measure behind them, and wrapped it around to measure the trees’ girth.

This year, after about 250,000 hugs between them, the work paid off.

Parker’s data, which showed the trunks gradually fattening over time, indicated that many of the trees were growing two to four times faster than expected. That raised questions about climate change’s impact on the age-old rhythms of U.S. forests.

It might also raise questions about Parker and members of his team, who say they enjoyed almost every minute of it.

Continue reading at The Washington Post . . .

Geocaching GPS Adventure at the Maryland Science Center in Baltimore

Friday, February 19th, 2010

[Editor’s note: If your on the East Coast the next couple months and looking to entertain kids (or your inner kid), check out the GPS Adventures geocaching experience at the Maryland Science Center in Baltimore, just an hour’s drive from Washington, DC. Requires modest entrance fee. After Baltimore, the exhibit heads to Redding, California, and then Dayton Ohio.  Thanks Dan!]

Republished from Maryland Science Center.
Video above is “The Thrill is in the Hunt” from the Pacific Science Center.

Opens this Saturday, thru April 18th.
Directions, hours and price »

Get Lost!

GPS Adventures is a life-sized maze exhibition introducing visitors to cutting-edge Global Positioning Systems (GPS) through Geocaching–a family friendly treasure hunting game.  More than three million people around the world are on the hunt for nearly a half million hidden treasures. In addition to hidden booty, these geocachers are finding the real treasure: reconnecting with family, community and nature in a meaningful way.

Exhibit highlights

  • Discover how GPS Technology is changing the way we live
  • Join the global treasure hunt movement known as geocaching
  • Use navigation, memory, and critical thinking to get through the maze

New navigation for a new kind of treasure hunt

GPS technology is changing the way we live.  It can be found in surprising places from cars to cell phones and is the backbone of the global treasure hunting game geocaching.  Get lost in the maze and learn how to find your way using GPS.  Visitors simulate a GPS adventure using a unique stamp card that leads you to your own Treasure City.  By collecting all 4 stamps you can better understand how satellite technology uses plotting to determine your exact location on the planet.

Understand how satellites pinpoint your position on the globe

Once visitors collect all 4 stamps visitors navigate the maze.  Navigate around impossible obstacles including waterfalls, cliffs and ravines to solve cache puzzles in four environments: city, local park, backcountry and an historic site to find secret codes and gain access to each of the satellite rooms.  Learn about maps, compasses and geography along the way.

Join the community of modern day treasure hunters–geocachers!

Meet Signal Frog—your helpful guide along the way.  Try on the latest outdoor gear and insert yourself into an outdoors-themed magazine cover.  Short, funny videos give an insider peak at the outdoor adventure of geocaching.  Interactive displays throughout the maze help visitors understand exactly how GPS works and how an outdoor treasure hunt using GPS navigation and deciphering clues has become a worldwide phenomenon with families and groups who embark on these 21st century treasure hunts.

State of Salmon Interactive Data Graphic (Periscopic)

Wednesday, February 17th, 2010

[Editor’s note: This Flash-based info graphic / report from Periscopic is a delight. They are based in Portland, Oregon and have an impressive client list. The company tag line of “Living in a world of data – and offering  a better view” is evident thru the project’s sophisticated quantitative analysis tools, accessed thru the Hydrography, Clusters, Historical, and List tabs. Thanks Wilson!]

Republished from Periscopic.

Salmon are a cultural and biological keystone of life around the Pacific Rim, uniquely linking freshwater and marine ecosystems. They form an irreplaceable mosaic of populations across land and water. This assessment, the first in a series on Pacific salmon, focuses on loss of biodiversity in one species – sockeye salmon.

Interact with the original at Periscopic . . .

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