Subscribe free to our newsletters via your
. Earth Science News .

Climate change boosted human development: study
by Staff Writers
Paris (AFP) May 21, 2013

Moore tornado a rarity: experts
Paris (AFP) May 21, 2013 - Tornados, among the most violent of atmospheric storms, rarely reach the size and brutality of the twister that swept through an Oklahoma City suburb on Monday, experts say.

And seldom do they hit built-up areas.

"Typically, they could be about 100 metres (110 yards) across, and they last maybe five to ten minutes on the ground," according to University of Reading meteorologist Ross Reynolds -- who said the people of Moore were in many ways unlucky.

They were confronted by a two-mile- (three-kilometre) wide storm that lasted about 45 minutes and was of a similar strength to the worst-ever tornado that hit the area 14 years ago but claimed fewer lives.

"It is bad luck that a tornado goes in a populated area, normally it is agriculture land... crops or farm buildings," said Reynolds.

"It is a horrible thing when they go through the cities -- the chances of that happening are very small" -- especially in such a sparsely populated region.

Revising a previous higher toll, officials said Tuesday that at least 24 people, including nine children, had died in the Oklahoma storm that packed winds of 166 to 200 miles per hour (267-322 kilometres per hour).

Tornados are spinning columns of air that touch the ground from massive cumulonimbus thunderstorm clouds.

They occur in regions of most continents except for the very coldest areas, and are also common in Argentina and Bangladesh.

The UK is said to get more tornadoes per square kilometre than the United States, but the central and southern American states of Texas, Oklahoma and Kansas get the most violent ones due to unique geographical and meteorological conditions.

Dubbed "Tornado Alley", this is where winds of widely varying temperatures -- warm and moist from the Gulf of Mexico, hot and dry from the desert and cool and dry from the Rocky Mountains and northern plains -- meet in volatile, potent storm clouds called "supercells" that can explode as tornadoes within half an hour from birth.

Most storms occur from May to June, and mainly between 4 pm and 9 pm, according to the US National Oceanic and Atmospheric Administration.

Tornado Alley can see three or four tornados per day in the high season, or about 1,200 for the entire country per year, but only about two percent reach dangerous levels with winds exceeding 265 kph and most of these hit land in rural areas.

According to Reynolds, weather conducive to tornado formation can be predicted a day in advance.

Local forecasters can then keep a careful eye on satellite and radar pictures of cloud- and rain-formation -- send out tornado-spotters to find the storms and estimate their speed and destination.

This allows officials to issue a 15-20-minute warning, hopefully enough time to dive into a tornado centre.

Experts say accurate records are too young and tornadoes too small and sporadic to predict whether they are likely to be impacted by climate change.

There was no proof that they were becoming more frequent or severe, said Reynolds.

"Climate models are currently unable to resolve small-scale phenomena such as tornadoes, and no models exist which can use climate model data to predict future tornado activity," said the UK Met Office.

But Andrew Barrett, also from the University of Reading, said warmer, moister conditions should "provide more energy for the types of storms that produce tornadoes in a warmer climate."

Early humans living in South Africa made cultural and industrial leaps in periods of wetter weather, said a study Tuesday that compared the archaeological record of Man's evolution with that of climate change.

Anatomically modern humans, Homo sapiens, first made their appearance in Africa during the Middle Stone Age which lasted from about 280,000 to 30,000 years ago.

Some of the earliest examples of human culture and technology are found in South Africa -- with fossil evidence of innovative spurts whose cause has left scientists puzzled.

The record reveals that a notable period of human advancement occurred about 71,500 years ago, and another between 64,000 and 59,000 years ago.

Examples of such innovation include the use of symbols, linked to the development of complex language, in engravings, the manufacture and use of stone tools and personal adornment with shell jewellery.

"We show for the first time that the timing of... these periods of innovation coincided with abrupt climate change," study co-author Martin Ziegler of the Cardiff University School of Earth and Ocean Sciences told AFP of the study in the journal Nature Communications.

"We found that South Africa experienced wetter conditions during these periods of cultural advance.

"At the same time, large parts of sub-Saharan Africa experienced drier conditions, so that South Africa potentially acted as a refugium for early humans."

Ziegler and a team reconstructed the South African climate over the past 100,000 years using a sediment core drilled out from the country's east coast.

The core shows changes in river discharge and rainfall.

"It offers for the first time the possibility to compare the archaeological record with a record of climate change over the same period and thus helps us to understand the origins of modern humans," Ziegler said by email.

Co-author Chris Stringer of London's Natural History Museum said the findings supported the view that population growth fuelled cultural advancement through increased human interactions.

"Such climate-driven pulses in southern Africa and more widely were probably fundamental to the origin of key elements of modern human behaviour in Africa and to the subsequent dispersal of Homo sapiens from its ancestral homeland," concluded the study.


Related Links
All About Human Beings and How We Got To Be Here

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Brain frontal lobes not sole centre of human intelligence
Durham UK (SPX) May 21, 2013
Human intelligence cannot be explained by the size of the brain's frontal lobes, say researchers. Research into the comparative size of the frontal lobes in humans and other species has determined that they are not - as previously thought - disproportionately enlarged relative to other areas of the brain, according to the most accurate and conclusive study of this area of the brain. It con ... read more

How should geophysics contribute to disaster planning

Rescuers dig for life after US tornado kills 24

Huge China sinkhole kills five: authorities

How should geophysics contribute to disaster planning?

3-D modeling technology offers groundbreaking solution for engineers

NASA Seeks High-Performance Spaceflight Computing Capabilities

SPUTNIX is granted a license for space activity

Stanford Engineers' New Metamaterial Doubles Up on Invisibility

Scientists explore roots of future tropical rainfall

World's smallest droplets

Shifts in global water systems markers of The Anthropocene epoch

New Stanford Nanoscavengers Could Usher In Next Generation Water Purification

Sea level influenced tropical climate during the last ice age

World's biggest ice sheets likely more stable than previously believed

Tropical air circulation drives fall warming on Antarctic Peninsula

Research into carbon storage in Arctic tundra reveals unexpected insight into ecosystem resiliency

Hong Kong hails the return of the duck

Argentine beef trade decimated by policy shifts

Keeping fruit, vegetables and cut flowers fresh longer

Danone strikes deals to meet Chinese taste for yogurt

6.0 quake off Russia's far-east Kamchatka coastline

Penn Research Helps Paint Finer Picture of Massive 1700 Earthquake

Five hurt as quake hits Algeria: medics

TD Alvin Marks Starts Of US Hurricane Season

Chinese vice premier on business visit to Zimbabwe

Madagascar security forces summon political rivals

African Sahel reels from ever more frequent crises: UN

SLeone, China sign huge infrastructure deal

Climate change boosted human development: study

Do salamanders hold the solution to regeneration

Brain frontal lobes not sole centre of human intelligence

Searching for Clandestine Graves with Geophysical Tools

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement