Mixing magma holds key to historic eruptions

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 03 August 2010

A new study has found that a mixing of two different types of magma is the key to the historic eruptions of Mount Hood, Oregon’s tallest mountain, and that eruptions often happen in a relatively short time – weeks or months – after this mixing occurs.

Mount Hood is the highest mountain in Oregon at 3429 metres

This behavior is different from that of most other Cascade Range volcanoes, including Mount Hood’s nearby, more explosive neighbor, Mt. St. Helens.

The research results are reported this week in the journal Nature Geoscience by geologists from Oregon State University (OSU) and the University of California at Davis, in work supported by the National Science Foundation (NSF).

“These results clarify details of the processes that trigger Mount Hood eruptions,” said Sonia Esperanca, program director in NSF’s Division of Earth Sciences, which funded the research. “Similar triggering processes may occur in several of Earth’s most active volcanoes.”

“The data will help give us a better road map to what a future eruption on Mount Hood will look like, and what will take place before it occurs,” said Adam Kent, a geoscientist at OSU. “It should also help us understand the nature of future eruptions and what risks they will entail.” Continue reading

Climate change could trigger ‘mega-disasters’

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 07 June 2010

Weather-related catastrophes brought about by climate change are increasing, the top UN humanitarian official said Sunday as he warned of the possibility of “mega-disasters”.

John Holmes, the UN Under-Secretary General for Humanitarian Affairs, said one of the biggest challenges facing the aid community was the problems stemming from changing weather patterns.

“When it comes to meteorological disasters, weather-related disasters, then there is a trend upwards connected with climate change,” Holmes, who is in Australia for high-level talks on humanitarian aid, told AFP.

“The trend is there in terms of floods, and cyclones, and droughts.”

Holmes, who is the UN’s emergency relief coordinator, said it had been a tough year due to January’s devastating earthquake in Haiti, which killed more than 250,000 people.

He said while earthquakes, such as the 7.0-magnitude quake which levelled the Haitian capital Port-au-Prince, were random, weather-related natural disasters were increasing in number and scale.

“It’s partly the very obvious things like the number of cyclones and the intensity of the cyclones, and the amount of flooding,” he said.

“But is also in slightly more invisible ways — in Africa with drought spreading, desertification spreading.”

Holmes said officials were particularly concerned about places where a combination of factors — such as large populations, or likelihood of earthquake, or susceptibility to rising sea levels — made them more vulnerable.

“One of things we worry about is mega cities could produce, at some point, a mega disaster,” he said. Continue reading