Colliding continents explains the unique geology of an area stretching from north of the Great Lakes along the northern shore of the St. Lawrence River to Labrador. According to an article appearing in January 2010 in the Canadian Journal of Earth Sciences, the Grenville Orogen, as it is known to geologists, shows several hallmarks of an ancient continent collision. Authors Andrew Hynes of McGill University and Toby Rivers of Memorial University of Newfoundland compare the zone to the Himilayas, where a small continent collided with the larger Asian continent.
The continents Amazonia and Laurentia are thought to have collided along this area starting 1100 million years ago, and slowly moving together over 100 million years. Metamorphic rock in the Ottawa area — including the area of yesterday’s earthquake — has a much higher pressure than rock in other areas of eastern Canada, as a result of the forces at work in the collision. While the geological history does not directly explain recent earthquakes, it sheds light on a section of the earth’s crust unique in the world, that we are still attempting to understand.
Today’s 5.0 M earthquake centred near Val-des-Bois, Quebec, is one of 18 earthquakes over 2.0 M in the area since January 2005, according to data from the Natural Resources Canada earthquake database. The area has shown steady seismic activity over the past five and a half years, with earthquakes ranging from undetectable to 4.5 M (in Thurso in February 2006). A 3.2 M earthquake occurred in the Val-des-Bois area March 6 of this year, and another of 2.6 M was centred several kilometres away Jan. 13. Data show a pattern of earthquakes every six months on average in an area extending east of Ottawa along the Ottawa river and northward. Earthquakes have been felt in Alfred, Buckingham, Thurso, Papineauville, Maniwaki, l’Orignal, Hawkesbury, and Wakefield. Patterns of earthquakes can indicate movement of faults or margins of techtonic plates, meaning residents of the western Quebec and eastern Ontario area may be in for more and stronger earthquakes for several years to come.
See also seismogram of today’s earthquake.
While the centenary of the Origin of Species has come and gone, it has left a legacy of thoughtful publications, films, and so on about evolution and genetics. At the recent Canadian Science Writers’ Association conference, I came across a booklet and Web site , suitable for non-specialists, that explain Darwin and the evolution of thinking about evolution. While Darwin’s conception was a breakthrough, it has taken the work of genetics and genomics to show the mechanism for favouring one feature over another. I’m particularly fascinated by the research into why music evolved, since it appears to serve no evolutionary purpose. Darwin found this a puzzler, and subsequent theories have ranged from courtship display (serenading works, evidently) to co-evolution with language to reinforcement of group ties. Epigenetics has now gone beyond genetics to explain changes how some traits can be inherited without a change in the underlying DNA. Current research shows that genes develop and spread in populations extremely quickly — from the Grants’ research showing that Galapagos finches change beak shape within one generation, to the discovery that the gene for lactose tolerance spread in humans over about 5000 years (faster than previously thought possible) as they cultivated cattle (Nature Genetics 2003 35(4):311-3). Our understanding of evolution is a moving target… as are we.
Avoiding fish high on the food chain in the Amazon because of the bioaccumulation of mercury from slash-and-burn agricultural techniques… Plastering homes with superior local cement to prevent the cracks where kissing bugs lurk, waiting to bite humans and transmit Chagas disease… Encouraging people in rural Lebanon to eat a traditional purslane-and-yogurt condiment rather than lower-protein, higher-fat coleslaw… These projects have shown that sustaining the local environment is essential to human health in many parts of the world. Analyzing the environment and health together — environmentally sound development and human development — is an emerging area dubbed “eco-health.” It crosses traditional disciplinary lines, involving social sciences (such as class and gender issues in developing communities) as well as public health and environmental sciences. Issues affecting communities must involve the people in them, so much of the research is “participative.” For more information about eco-health and details of these projects, visit the International Development Research Centre site.
If you’re blogging about someone else’s blog, is it a meta-blog? Today’s meta-blog post is about desmogblog, a blog devoted to unmasking climate change deniers. The minds behind desmogblog include Jim Hoggan, well-known Vancouver-based public relations man and chair of the David Suzuki Foundation, and his co-author, Richard Littlemore, of Climate Cover-up . Hoggan spoke yesterday at the Canadian Science Writers’ Association meeting in Ottawa, where jaded science writers were honestly stunned and shocked by his information about energy-industry manipulation of the public agenda in the US. He presented strong evidence of industry front groups posing as grassroots organizations (“astroturf” groups) in order to confuse citizens and policy-makers. As a seasoned PR professional, Hoggan has a quick way with a phrase, but he speaks out against using the tactics of PR to be duplicitious or deceitful. His blog uses all the tricks of the trade, but to expose, not obfuscate. This is not the climate change debate (because, in the scientific arena, there isn’t one), but the meta-discussion about how the “debate” has been concocted and foisted on an ignorant public.