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Shock Wave - CBC Doc Zone
Written by CBC Doc Zone   

Sunday March 22, 2009 at 10 pm ET/PT on CBC Newsworld

Earthquakes, like the one that caused the Indian Ocean disaster of December 26, 2004, tend to repeat themselves. The waves they generate can circle the globe with devastating consequences. Recently, scientists discovered that the Cascadia Subduction Zone off the west coast of North America has ruptured at least 37 times in the past 10,000 years and it will rupture again...but when?

The crack in the ocean floor from Cape Mendocino, California to central Vancouver Island is nearly identical to the subduction zone that ruptured off Sumatra, which led to the tsunami that killed approximately 230,000 people. The Pacific Northwest can expect a nearly identical earthquake. Five major cities (Vancouver, Victoria, Seattle, Portland and Sacramento) plus hundreds of small towns along a thousand kilometres of coastline will be heavily damaged. The first tsunami waves will hit the beach twenty minutes later.

Last Updated on Friday, 20 March 2009 18:16
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Spilled diesel more deadly to fish when dispersed: study
Written by CBC News   
It's a macabre case of less is more: spilled diesel is more toxic to fish when it has been broken up into small droplets and dispersed in the water than when it is concentrated in large pools on the surface, Canadian researchers have found.

"Diesel, when it floats in nice calm water with no turbulence actually is not particularly toxic, but what we showed with dispersant studies was that as soon as you mix it, materials in the oil get into the water much more readily and therefore harm fish," biologist Peter Hodson told CBCNews.ca Friday.

Hodson conducted the study with other researchers at Queen's University in Kingston, Ont., and Victoria, B.C.-based environmental consultant Lizzy Mos. The results, published in the March issue of Environmental Toxicology and Chemistry, suggest that spilled diesel could be much more dangerous to fish if it gets into rushing rivers and other situations where it might get mixed into the water.

Detergents are often used as chemical dispersing agents during oil spills on the ocean. The detergents break the oil up into tiny droplets, allowing it to be more easily diluted and broken down by light and bacteria. It also makes the oil less harmful to seabirds, which can end up coated in oil concentrated on the surface.

Hodson and his group used detergents to disperse simulated diesel spills in his lab, and found that young rainbow trout were much more likely to sicken or even die when a dispersing agent was used than when it wasn't. He believes aquatic organisms are likely to be similarly affected.
Fresh water often affected

Diesel spills are common in fresh water, because diesel is often transported by truck, rather than by ship on the sea, and thus released during collisions or rollovers from the truck's fuel tanks, Hodson said.

Detergents aren't usually used to disperse freshwater diesel spills, as some dispersing agents used in the past were known to be toxic. However, Hodson's study found the detergent he used wasn't the problem, as the fish were unharmed by detergent mixed with non-toxic mineral oil. Instead, the results suggest that it's the diesel that is toxic and the mixing that makes it more harmful to the fish.

Hodson hopes to undertake further studies in which the diesel is mixed mechanically rather than with a dispersant.

But for the moment, the results seem to show that cleaning up diesel spills is extra urgent if there is a risk it could flow in choppier waters, he said.

"The biggest single solution to this problem is not to spill oil at all," he said.

Where that's impossible, he added, "You really want to contain it on site and prevent it from getting into turbulent water."
Last Updated on Sunday, 04 April 2010 22:43
 
Canada at grave risk if national disaster strikes: Senate report
Written by CBC News   

Attempts to improve emergency response system have been 'lethargic'

Canada's preparedness to deal with major national disasters and emergencies "gives new meaning to the word 'discouraging,'" says a report released Tuesday by the Senate's committee on national security and defence.

An unidentified health care worker wipes a door handle at North York General Hospital in Toronto, on May 27, 2003, during the SARS outbreak.
An unidentified health care worker wipes a door handle at North York General Hospital in Toronto, on May 27, 2003, during the SARS outbreak. (Aaron Harris/Canadian Press

Canadian governments have failed to treat major human and natural disasters, like the 1985 Air India bombing and the 2003 SARS epidemic, as the major wake-up calls that they should have been, the report says.

Instead, bureaucratic wrangling and a lack of co-ordination among all levels of government are hindering much-needed improvements to the system, the report says.

The report criticizes provincial and federal governments for a "lethargic" approach to emergency preparedness that doesn't give adequate or flexible enough funding to emergency services.

"Committee members know that it isn't easy making progress on any file that crosses jurisdictional lines, particularly when some provinces are openly antagonist about having their jurisdictions invaded no matter how serious the issue," the report says.

"Nonetheless, we are talking about the possibility of widespread physical and economic disaster to Canadians here, and somebody has to cut the Gordian knot."

First responders to disasters haven't been instructed on lessons learned from past disasters, the report says.

Last Updated on Friday, 20 March 2009 16:52
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