Earth ChangesS

Better Earth

Magma pulses may reveal Earth's 'heartbeat'

© Martin Rietze / WestEnd61 / RexEvidence from distant parts of Earth's crust suggests the core is pulsing, sending up a regular batch of magma to the surface.
Earth may have a heartbeat. Evidence from Hawaii and Iceland hints that the planet's core may be dispatching simultaneous plumes of magma towards the surface every 15 million years or so.

If the hypothesis is true, it would revolutionise our ideas of what's happening far below our feet. Independent scientists contacted by New Scientist were split, with some scornful and others intrigued.

Rolf Mjelde of the University of Bergen and Jan Inge Faleide of the University of Oslo, both in Norway, used seismological data to measure the thickness of Earth's crust between Iceland and Greenland. Iceland is on the Mid-Atlantic Ridge, where magma wells up to form fresh crust.

Better Earth

Earth's 'hum' may reveal stormier climate

The world is abuzz with climate change - in more ways than one. Swelling waves and rising sea levels can be detected in the way the planet "hums", says an oceanographer.

Peter Bromirski, of the Scripps Institution of Oceanography at the University of California, San Diego, says that seismic listening stations provide a long-term record of how the amount of energy reaching the world's shores is changing with climate change.

Most geologists who study seismology try to eliminate background noise in their data, but a handful of researchers have started to take a closer look at it.

They have identified at least three different types of "noise", including the Earth's hum, which was first discovered in 1998. The other two are called "microseisms" - tiny earthquakes - and have slightly different acoustic properties.


Earthquake Magnitude 5.4 in Southern Xinjiang China

Xinjiang Earthquake 1
A strong earthquake occurred in Southern Xinjiang, China.

Arrow Down

Australia: State of emergency declared in Queensland as freak weather moves south

Brisbane Floods 5
© BOMCurrent infrared satellite image from MTSAT-1R
Weather conditions have eased on the Gold Coast after strong winds and heavy rain pounded the south-east of Queensland, prompting Premier Anna Bligh to declare a state of emergency.

Nearly all of Brisbane's major arterial roads are damaged, hospitals have cancelled services, and emergency crews have been stretched to the limit by the city's most extensive flooding since 1974.


Mockingbirds Can Identify People and Quickly React to Those They Don't Trust

© University of FloridaA mockingbird grazing University of Florida biology major Devon Duffy, in Gainesville, Fla., in an attempt to drive her away from its nest on the university campus.
Mockingbirds may look pretty much alike to people, but they can tell us apart and are quick to react to folks they don't like. Birds rapidly learn to identify people who have previously threatened their nests and sounded alarms and even attacked those folks, while ignoring others nearby, researchers report in Tuesday's edition of Proceedings of the National Academy of Sciences.

"This shows a bird is much more perceptive of its environment than people had previously suspected," said Douglas J. Levey, a professor in the zoology department of the University of Florida.

"We are a part of their environment and we are a concern to them," Levey said in a telephone interview.

The researchers are studying mockingbirds as part of an effort to better understand how species adapt to urbanization.

With more and more areas being converted into towns and cities, animals that adapt well seem to be those that are especially perceptive about their environment, he said.

Better Earth

Bird Songs Change With Environment

White-crowned sparrow
© iStockphoto/Chad IvanyWhite-crowned sparrow. When the going gets rough, the tough apparently sing slower.
Just as a changing radio landscape has made it tough for Foghat to get much airplay these days, so it is for birdsongs according to new research published in The American Naturalist.

Behavioral ecologist Elizabeth Derryberry (Louisiana State University) has found that the songs of white-crowned sparrows change over time in response to changing habitats. The research sheds light on the factors that drive the evolution of mating signals in birds.

Derryberry says she first noticed that sparrows seem to be changing their tunes while working on her doctoral research. She ran across some old recordings of classic sparrow songs from 1970, and noted that the old tunes seemed a little different from the ones the kids are singing today.


U.S.: Destructive Ants Marching on San Antonio

Crazy Ant
© UnknownClose-up view of a Raspberry crazy ant. Entomologists say the public must learn about the destructive Rasberry crazy ant and help prevent them from spreading.
A destructive menace is heading west on Interstate 10 toward San Antonio.

It's the crazy Raspberry ant that was first spotted in Houston in 2002. No one knows where it came from or how to control it, but it reproduces faster than any insect experts have ever seen.

"This is an alien species," says Sam Houston State University Entomologist Dr. Jerry Cook. "This is in higher densities than any other insects I've ever seen. They number in the billions and cover everything around them."

"Where you'll have 200,000 ants in a big fire ant mound, you'll have billions of crazy ants in one area, in that one group. They form a carpet of ants over acres that is several inches thick."

Eye 2

Venom is key to Komodo dragon's killing power

Kimodo Dragon
© David Hill/RexThose jaws hide razor-sharp teeth and venom glands
Far from harbouring toxic bacteria in their mouths as long believed, Komodo dragons produce venom from complex glands in their lower jaws, according to a team led by Bryan Fry of the University of Melbourne, Australia.

The study also suggests that the largest venomous creature to have ever existed was a 5.5-metre-long ancestor of the Komodo - the now extinct Megalania lizard.

Man-eating monitor

Komodos, which live on three Indonesia islands, repeatedly slash at their prey until they are weak enough to eat. They can take down a 40-kilogram Rusa deer, and kill a full-grown human.

For decades, wildlife documentaries have promoted the idea that Komodo dragons owe their success as predators to toxic bacteria in their saliva - a claim bolstered by a 2002 study reporting deaths among lab mice injected with their saliva.


On the Central Question of Climate Sensitivity

Monckton question on sensitivity
© Lord Monckton of Brenchley
The Honorable Joe Barton and the Honorable Fred Upton
17 May 2009


Following my recent testimony before the Energy and Commerce Committee of the House, you kindly directed a question to me via the Committee Clerks -
"Is there any dispute that, as you say, "How much warming will a given proportionate increase of CO2 concentration cause?" is the central question of the climate debate?

a) "If so, what is it?
b) "If not, why hasn't the scientific community participating in the IPCC caught the matter?"
I apologise that my reply is a little late. I have taken some time consulting scientific experts. No discourtesy either to you personally or to the Committee was intended.

The "climate sensitivity" question, as it is called, is indeed the central question, on which all else depends.
The answer to your principal question is that there is no dispute at all about whether the question "How much warming will a given proportionate increase of CO2 concentration cause?" is the central question of the climate debate. The "climate sensitivity" question, as it is called, is indeed the central question, on which all else depends. If climate sensitivity is high, as the IPCC maintains it is, then much "global warming" can be expected, whereupon the questions that fall to be answered are how much damage (if any) the warming predicted by the IPCC may cause, and whether or to what extent it lies within our power to mitigate or adapt to the predicted warming and any consequent damage, and whether the costs of mitigation might outweigh the costs of the damage the warming may cause, and whether or to what extent it would be cheaper to adapt to any "global warming" that might occur, as and if necessary.


Update: Earthquake Magnitude 4.7 in Greater Los Angeles Area

LA Quake 1
A magnitude 4.7 earthquake struck about 3 miles east of Los Angeles International airport at 8:39 p.m. (PDT) local time, at a depth of 8.5 miles. Given that the location is in a densely populated part of the Los Angeles basin, it was widely felt.

Initial estimates from the USGS ShakeMap indicate that although strong shaking will have been felt by many people, damage is expected to be light.