New ‘ocean’ being born in Africa

LONDON (UPI) — A new ocean is being born in Africa that will eventually split the continent in two, British researchers say.

Scientists at Britain’s Royal Society say a 40-mile crack in the Earth opened in Ethiopia in 2005 and has been growing ever since, the BBC reported Friday.

The crack will eventually became the sea bed of a new ocean that will divide Africa in two, though the process will require about 10 million years, scientists say.

Used to understanding planetary changes on timescales involving millions of years, scientists say the crack in the remote Afar region of Ethiopia is dramatic in the speed at which it is growing.

The 40-mile crack opened to a width of 22 feet in just 10 days, they say.

Ultimately, they say, the horn of Africa will split from the continent, and the crack, in a region below sea level, will fill with salt water.

“It will pull apart, sink down deeper and deeper and eventually … parts of southern Ethiopia, Somalia will drift off, create a new island, and we’ll have a smaller Africa and a very big island that floats out into the Indian Ocean,” said Dr. James Hammond, a seismologist from the University of Bristol.

Copyright 2010 by United Press International

Sourced & published by Henry Sapiecha

Why Icicles Are Long And Thin

Mathematical Physics Explains

How Icicles Grow

When droplets of melted snow drip down an icicle, they release small amounts of heat as they freeze. Heated air travels upwards and helps slow down the growth of the icicle’s top, while the tip is growing rapidly. Knowledge of the mathematical equations that govern icicle growth — the same that apply to stalactites — could help in the prevention of icicle formation on power lines.

Icicles can be dangerous and deadly, yet they can create some of the most amazing winter scenes. And for scientists, those winter scenes are playgrounds for discovery.

It’s on those playgrounds that experts in physics and mathematics are building their theories on what it takes to create an icicle.

We all know icicles form when melting snow begins dripping down a surface. But what scientists didn’t know is how their shape is formed. What makes each icicle different?

University of Arizona Physicist Martin Short turned to mathematics to find out.

“Icicles have a certain mathematical shape, and this mathematical shape is universal among icicles,” Short tells DBIS.

So what is the math behind an icicle?

“Here I’ve drawn the profile of an icicle. Here is the height, and here’s the radius … Here’s the profile here, and I’ve written the formula here. The height is proportional to the radius to the four-thirds,” he says.

What does the formula have to do with an icicle’s shape? “It kind of looks like a carrot,” says Short. “It starts out flat and then sort of up as you go.”

As water drips onto an icicle and freezes, it releases heat. The warm air rises up the sides of the icicle. Short says that warm air layer acts like a blanket that’s an insulator, and so the blanket is very thin near the tip and thick at the top. That allows the top to grow very slowly and the tip to grow rapidly — creating a long, thin icicle.

It’s the same equation scientists use to study stalactites in caves, but instead of water, stalactites are formed by the buildup of calcium left after the water evaporates.

“If we know the mechanisms by which stalactites form, well, we could better preserve our natural caves that we have here, and try to stop them from eroding,” Short says.

And now that scientists know how icicles are made, it could lead to breakthroughs to prevent them from forming on power lines and trees.



BACKGROUND: Researchers at the University of Arizona have found that the same mathematical formula used to describe the shape of stalactites that form in caves also describes the shape of icicles. This is surprising because the physical processes that form icicles are very different from those that form stalactites. Both have a unique underlying shape, resembling a kind of elongated carrot. This sheds light into the physics of how drips of icy water can swell into long, skinny spikes (icicles).

HOW THEY FORM: Stalactites are formations that hang from the ceilings of caves, formed when water erodes limestone and taking the calcium carbonate. As the water drips inside the cave and evaporates, it leaves behind the calcium, which forms a stalactite. The continued diffusion of carbon dioxide gas fuels the growth of a stalactite. In contrast, heat diffusion and a rising air column are keys to an icicle’s growth. Icicles form when melting snow begins dripping down from a surface such as the edge of a roof. There must be a constant layer of water flowing over the icicle in order for it to grow. The growth is caused by the diffusion of heat away fro the icicle by a thin fluid layer of water, and the resulting updraft of air traveling over the surface. That updraft occurs because the icicle is generally warmer than its surrounding environment, and thus convective heating causes the surrounding air to rise. As the rising air removes heat from the liquid layer, some of the water freezes, and the icicle grows thicker and elongates.

PUT TO THE TEST: To compare the predicted shape to real icicles, the researchers compared pictures of actual icicles with their predicted shape. They found that it doesn’t matter how big or small the actual icicles were, they could all fit the shape generated by the mathematical equation. The next step is to solve the problem of how ripples are formed on the surfaces of both stalactites and icicles.

ICE, ICE, BABY: Ice is the frozen form of liquid water. The same substance will behave differently at various temperatures and pressures. Water (H2O) is the most familiar example. It can be a solid (ice), a liquid (water), or a gas (steam), but it is still made up of molecules of H2O, so its chemical composition remains unchanged. At sea level, water freezes at 32 degrees Fahrenheit (0 degrees Celsius) and boils at 212 degrees Fahrenheit (100 degrees Celsius), but this behavior changes at different altitudes because the atmospheric pressure changes. In fact, get the pressure low enough and water will boil at room temperature. The critical temperature/pressure point at which H2O changes from one form to another is called a phase transition.

The American Meteorological Society and the American Geophysical Union contributed to the information contained in the video portion of this report.

Sourced and published by Henry Sapiecha 12th June 2010

Climate change killing lizards worldwide

SANTA CRUZ, Calif. (UPI) — Twenty percent of all lizard species could be extinct by 2080 because of rising temperatures involved in climate change, a California researcher said.

Lizards worldwide are far more susceptible to climate-warming extinction than previously thought because many species already live at the edge of their thermal limits, said Barry Sinervo of the Department of Ecology and Evolutionary Biology at the University of California, Santa Cruz.

Sinervo and colleagues from around the world said they reached their conclusions after comparing field studies of lizards in Mexico to lizard studies from other countries.

Rising temperatures already have driven an estimated 12 percent of Mexico’s Sceloporus lizard population to extinction, the scientists wrote in a recent issue of the journal Science.

“We are actually seeing lowland species moving upward in elevation, slowly driving upland species extinct, and if the upland species can’t evolve fast enough then they’re going to continue to go extinct,” Sinervo said in a release from the university Thursday.

Sourced and published by Henry Sapiecha 7th June 2010