Scientists from the NIOZ Royal Netherlands Institute for Sea Research obtained for the first time a detailed temperature record for tropical central Africa over the past 25,000 years. They did this in cooperation with a German colleague from the University of Bremen, The scientists developed an entirely new method to reconstruct the history of land temperatures based on the molecular fossils of soil bacteria.
They applied the method to a marine sediment core taken in the outflow of the Congo River. This core contained eroded land material and microfossils from marine algae. The results show that the land environment of tropical Africa was cooled more than the adjacent Atlantic Ocean during the last ice-age. This large temperature difference between land and ocean surface resulted in drier conditions compared to the current situation, which favours the growth of a lush rainforest. These findings provide further insight in natural variations in climate and the possible consequences of a warming earth on precipitation in central Africa. The results will be published in this week's issue of 'Science'.
Earth Changes
Scientists have identified an expanse of rock in Greenland as a remnant of Earth's crust dating back 3.8 billion years, a finding that shows the dynamic geological process called plate tectonics was occurring early in our planet's history.
Writing in the journal Science on Thursday, a team led by Harald Furnes of the University of Bergen in Norway said these ancient layered rocks from southwestern Greenland originally were formed on the sea floor of primordial Earth.
They are made up of thin sheets of formerly molten rock, and look a bit like a multilayered cake. They contain a mix of volcanic rocks associated with the formation of new crust.
Plate tectonics is a theory broadly accepted by geologists relating to the movement of the gargantuan plates that make up the planet's surface. These plates, largely corresponding to the continents, are in constant gradual motion.
Writing in the journal Science on Thursday, a team led by Harald Furnes of the University of Bergen in Norway said these ancient layered rocks from southwestern Greenland originally were formed on the sea floor of primordial Earth.
They are made up of thin sheets of formerly molten rock, and look a bit like a multilayered cake. They contain a mix of volcanic rocks associated with the formation of new crust.
Plate tectonics is a theory broadly accepted by geologists relating to the movement of the gargantuan plates that make up the planet's surface. These plates, largely corresponding to the continents, are in constant gradual motion.
Emergency services and harbour authorities braced themselves for a third round of damage from the spring equinox tidal action on Monday night.
The Zululand coast took a considerable pounding yesterday as Mother Nature unleashed her fury twice.
Richards Bay's beachfront took a hammering early on Monday as huge waves, driven by gale-force winds, scoured the beach and came within metres of crashing into the municipal beach office.
The beachfront and beaches around the harbour waterfront suffered further damage during Monday afternoon's phenomenal tide, which came close to causing major flood damage to the TuziGazi Waterfront.
Lifeguards evacuated the two-storey building and removed all valuables yesterday morning because municipal officials feared that although the structure rested on deep piles, erosion could make it unstable.
The Zululand coast took a considerable pounding yesterday as Mother Nature unleashed her fury twice.
Richards Bay's beachfront took a hammering early on Monday as huge waves, driven by gale-force winds, scoured the beach and came within metres of crashing into the municipal beach office.
The beachfront and beaches around the harbour waterfront suffered further damage during Monday afternoon's phenomenal tide, which came close to causing major flood damage to the TuziGazi Waterfront.
Lifeguards evacuated the two-storey building and removed all valuables yesterday morning because municipal officials feared that although the structure rested on deep piles, erosion could make it unstable.
ANTANANARIVO - A cyclone that swept across Madagascar last week killed at least 69 people and made tens of thousands homeless in the north of the Indian Ocean island, officials said on Friday.
Mudslides have buried whole villages, rivers have burst their banks and roads have been cut off since Cyclone Indlala struck on March 15.
Mudslides have buried whole villages, rivers have burst their banks and roads have been cut off since Cyclone Indlala struck on March 15.
A mysterious decimation of bee populations has German beekeepers worried, while a similar phenomenon in the United States is gradually assuming catastrophic proportions. The consequences for agriculture and the economy could be enormous.
The theory that Earth once underwent a prolonged time of extreme global freezing has been dealt a blow by new evidence that periods of warmth occurred during this so-called 'Snowball Earth' era.
Analyses of glacial sedimentary rocks in Oman, published online today in Geology, have produced clear evidence of hot-cold cycles in the Cryogenian period, roughly 850-544 million years ago. The UK-Swiss team claims that this evidence undermines hypotheses of an ice age so severe that Earth's oceans completely froze over.
Using a technique known as the chemical index of alteration, the team examined the chemical and mineral composition of sedimentary rocks to search for evidence of any climatic changes. A high index of alteration would indicate high rates of chemical weathering of contemporary land surfaces, which causes rocks to quickly decompose and is enhanced by humid or warm conditions. Conversely, a low chemical index of alteration would indicate low rates of chemical weathering during cool, dry conditions.
Analyses of glacial sedimentary rocks in Oman, published online today in Geology, have produced clear evidence of hot-cold cycles in the Cryogenian period, roughly 850-544 million years ago. The UK-Swiss team claims that this evidence undermines hypotheses of an ice age so severe that Earth's oceans completely froze over.
Using a technique known as the chemical index of alteration, the team examined the chemical and mineral composition of sedimentary rocks to search for evidence of any climatic changes. A high index of alteration would indicate high rates of chemical weathering of contemporary land surfaces, which causes rocks to quickly decompose and is enhanced by humid or warm conditions. Conversely, a low chemical index of alteration would indicate low rates of chemical weathering during cool, dry conditions.
Global warming solutions that would earn a laugh from many of us are getting some serious attention by scientists.
With the impacts of global warming being felt around the globe, an insurance policy of sorts may be needed in case the effects are faster and more dramatic that what can be fought with more traditional methods like efficiency, renewable power, etc. Here's a sample of the more interesting scenarios that are being considered and studied:
With the impacts of global warming being felt around the globe, an insurance policy of sorts may be needed in case the effects are faster and more dramatic that what can be fought with more traditional methods like efficiency, renewable power, etc. Here's a sample of the more interesting scenarios that are being considered and studied:
Some of the world's largest and best-known rivers are at risk of drying up as a result of climate change, pollution and bad planning, a report warned today.
The study by the environment group, WWF, focuses on the ten rivers most danger of drying up or dying, and warns that, without action, the world faces "a freshwater emergency".
The study by the environment group, WWF, focuses on the ten rivers most danger of drying up or dying, and warns that, without action, the world faces "a freshwater emergency".
A snapshot of ocean conditions taken during Hurricane Ivan in 2004 has yielded new clues about the dynamics of storm surges that could help meteorologists make more accurate predictions, a study released Thursday said.
Weather forecasters typically rely on data about surface winds and turbulence to try and figure out just how much a storm has churned up the ocean and what the resulting storm surge will look like -- the kind of surge that walloped New Orleans after Hurricane Katrina in 2005.
Weather forecasters typically rely on data about surface winds and turbulence to try and figure out just how much a storm has churned up the ocean and what the resulting storm surge will look like -- the kind of surge that walloped New Orleans after Hurricane Katrina in 2005.
Geophysicist urges public, policy makers to consider all tectonic boundaries as lethal
The 2004 Sumatra-Andaman earthquake and resulting tsunami are now infamous for the damage they caused, but at the time many scientists believed this area was unlikely to create a quake of such magnitude. In the March 23 issue of the journal Science, a geophysicist from Rensselaer Polytechnic Institute urges the public and policy makers to consider all subduction-type tectonic boundaries to be "locked, loaded, and dangerous."
"Seismologists have long tried to determine which subduction boundaries are more likely than others to break," says Robert McCaffrey, professor of earth and environmental sciences at Rensselaer. "Yet, the great earthquake of 2004 ruptured a segment that was thought to be among the least likely to go."
On Dec. 26, 2004, the earth beneath the Indian Ocean buckled and ruptured, unleashing one of the largest earthquakes in recorded history. Shockwaves from the magnitude 9.2 (M9) quake created a wall of rushing water that devastated communities up to 1,000 miles away.
The 2004 Sumatra-Andaman earthquake and resulting tsunami are now infamous for the damage they caused, but at the time many scientists believed this area was unlikely to create a quake of such magnitude. In the March 23 issue of the journal Science, a geophysicist from Rensselaer Polytechnic Institute urges the public and policy makers to consider all subduction-type tectonic boundaries to be "locked, loaded, and dangerous."
"Seismologists have long tried to determine which subduction boundaries are more likely than others to break," says Robert McCaffrey, professor of earth and environmental sciences at Rensselaer. "Yet, the great earthquake of 2004 ruptured a segment that was thought to be among the least likely to go."
On Dec. 26, 2004, the earth beneath the Indian Ocean buckled and ruptured, unleashing one of the largest earthquakes in recorded history. Shockwaves from the magnitude 9.2 (M9) quake created a wall of rushing water that devastated communities up to 1,000 miles away.
