Earth ChangesS


Bizarro Earth

Pollution slowly killing world's coral reefs

Cancun, Mexico - Dainty blue fish dart around coral shaped like moose antlers near the Mexican resort of Cancun, but sickly brown spots are appearing where pollution threatens one of the world's largest reefs.

Parts of the reef, nestled in turquoise waters, have died and algae -- which feed on sewage residues flowing out of the fast-growing resort city -- has taken over.

Coral reefs like Chitales, near the northern tip of a Caribbean reef chain stretching from Mexico to Honduras, are dying around the world as people and cities put more stress on the environment.

Climate change alone could trigger a global coral die-off by 2100 because carbon emissions warm oceans and make them more acidic, according to a study published in December.

But local environmental problems like sewage, farm runoff and overfishing could kill off much of the world's reefs decades before global warming does, said Roberto Iglesias, a biologist from UNAM university's marine sciences station near Cancun.

"The net effect of pollution is as bad or maybe worse than the effects of global warming," said Iglesias, a co-author of the study in the journal Science on how climate change affects reefs.

Human waste like that from Cancun's hotels and night spots aggravates threats to coral worldwide like overzealous fishing which hurts stocks of fish that eat reef-damaging algae.

Bizarro Earth

Stalagmites May Predict Next Big One Along The New Madrid Seismic Zone

Small white stalagmites lining caves in the Midwest may help scientists chronicle the history of the New Madrid Seismic Zone (NMSZ) - and even predict when the next big earthquake may strike, say researchers at the Illinois State Geological Survey and the University of Illinois at Urbana-Champaign.

Small white stalagmites
© K. HackleySmall white stalagmites. Insert: one stalagmite cut vertically in half, showing generations of growth with the white one on top.
While the 1811-12, magnitude 8 New Madrid earthquake altered the course of the Mississippi River and rung church bells in major cities along the East Coast, records of the seismic zone's previous movements are scarce. Thick layers of sediment have buried the trace of the NMSZ and scientists must search for rare sand blows and liquefaction features, small mounds of liquefied sand that squirt to the surface through fractures during earthquakes, to record past events. That's where the stalagmites come in.

The sand blows are few and far between, said Keith Hackley, an isotope geochemist with the Illinois State Geological Survey. In contrast, caves throughout the region are lined with abundant stalagmites, which could provide a better record of past quakes. "We're trying to see if the initiation of these stalagmites might be fault-induced, recording very large earthquakes that have occurred along the NMSZ," he said.

Magnify

Australia: Unusual haze engulfs Gold Goast - depth of mystery debated

Mysterious Haze at Gold Coast
Hazy... the salt spray at Main Beach, while conditions remain clear at Southport (inset)

A salty haze over parts of the Gold Coast this morning has dramatically reduced visibility in some areas - while others are perfectly clear.

Comment: The unusual appearance of the thick and localised haze received wide media coverage in Queensland. Some of the reader comments sent to The Courier Mail's website are interesting. Here are two of them...

Marko of South Brisbane
"I was at Surfers Paradise today and I saw some very unusual cloud conditions at about mid-day. It was a hot and windy blue sky day - which is not unusual. Small and isolated puffy clouds came in quickly from the sea, and swept past the top floors of the Coast towers. No other types of cloud were in the sky."
Gillian Lane of Southport
"Actually being on the Gold Coast, I can tell you that the hazy conditions were really quite remarkable and most certainly newsworthy. It was almost like cloud at ground level at Southport."



Attention

Erupting Volcano in Chile

The Chilean volcano Chaiten has been erupting since September 23, 2008. This activity has been registered on the website, when the volcano icon turned from brown to red. A little later, magma flow was detected by the Modis fire detection system, shown by a yellow spot in the middle of the volcano symbol.

Attention

Shiveluch Volcano, Kamchatka, Russia

An eruption occurred at Shiveluch volcano in Russia on 25th September 2008. At 8 am local time the eruption produced an ash column 4.5 km high. The eruption was accompanied by earthquakes. There was no threat to nearby communities according to the Geophysics Service of the Russian Academy of Sciences.

Target

Like an arrow: Jumping insects use archery techniques

froghopper
© Burrows et al, BMC Biology 2008An adult froghopper
Froghoppers, also known as spittlebugs, are the champion insect jumpers, capable of reaching heights of 700 mm - more than 100 times their own body length. Research published today in the open access journal BMC Biology reveals that they achieve their prowess by flexing bow-like structures between their hind legs and wings and releasing the energy in one giant leap in a catapult-like action.

Bulb

How the jellyfish got its sting: From a bacterium, surprisingly

Image
© NHPA/A.N.T. PHOTO LIBRARYThe venom of the box jellyfish can paralyse the central nervous system of its victims
Jellyfish may owe thanks to a humble bacterium for their ability to sting prey. Scientists have found that one of the genes necessary for them to sting is similar to a gene in bacteria, suggesting the ancestors of jellyfish picked up the gene from microbes. The research is published this week in Current Biology.

"The result was a great surprise," says developmental biologist Nicolas Rabet of the Pierre and Marie Curie University in Paris, France, who led the team. "[This kind of] horizontal gene transfer is often neglected, and could sometimes be more important than we thought." Unlike vertical gene transfer from parent to offspring, the horizontal variety happens between organisms, or even between different species. Common in microbes, it has only been described a few times in animals. Japanese beetles have picked up sequences from a parasitic bacterium and microscopic aquatic creatures called bdelloid rotifers have collected genes from bacteria, fungi and plants.

X

Six dead in Georgian landslide

Six people were killed overnight in a landslide in Georgia's Black Sea autonomous republic of Adzharia, a government source said on Monday.

The landslide struck a mountainous village, completely destroying one house. The landslide was caused by recent heavy rains in the region.

Stop

Typhoon Jangmi kills two in Taiwan

Two people were killed when a powerful typhoon struck Taiwan over the weekend, national media reported on Monday.

An 82-year-old man drowned after being swept into a flooded rice field, while an 18 year-old girl was killed by a fallen electric cable as Typhoon Jangmi wrecked havoc in Taiwan.

Better Earth

Sounds Travel Farther Underwater As World's Oceans Become More Acidic

It is common knowledge that the world's oceans and atmosphere are warming as humans release more and more carbon dioxide into the Earth's atmosphere. However, fewer people realize that the chemistry of the oceans is also changing - seawater is becoming more acidic as carbon dioxide from the atmosphere dissolves in the oceans.

increasing carbon dioxide
© MBARI; Base image courtesy of David FiersteinThis illustration shows how increasing carbon dioxide in the atmosphere leads to an increase in the acidity of seawater, which in turn allows sounds (such as whale calls) to travel farther underwater.
According to a paper to be published this week by marine chemists at the Monterey Bay Aquarium Research Institute, these changes in ocean temperature and chemistry will have an unexpected side effect - sounds will travel farther underwater.

Conservative projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that the chemistry of seawater could change by 0.3 pH units by 2050 (see below for background information on pH and ocean acidification). In the October 1, 2008 issue of Geophysical Research Letters, Keith Hester and his coauthors calculate that this change in ocean acidity would allow sounds to travel up to 70 percent farther underwater. This will increase the amount of background noise in the oceans and could affect the behavior of marine mammals.