增城市文化历史气息多市再添

市议员帕克(左2)和市府官员在其中一块牌匾前合影。(余曦摄)

本文 来 自 家 园 网

多伦多市政府昨天为8位曾在多伦多居住和工作的文化名人揭匾。这是多伦多一个新的项目，由本市前桂冠诗人Dennis Lee发起。从去年开始，今年是第二批。

家 园 网

市议员帕克代表市长福特主持了宣布仪式。他表示，一个城市的记忆，反映了一个城市的历史。

昨天宣布的8位多伦多文化名人是：Celia Franca(1921-2007)，国家芭蕾舞学院创始艺术指导，本国芭蕾舞艺术奠基人；Jane Jacobs (1916-2006)，作家、活动家，城市规划的领袖人物；William James (1866-1949)，前卫摄影师，城市编年史记录者；E. J. Lennox (1854-1933)著名建筑师，他的作品包括旧市议厅、Casa Loma和King Edward酒店。

不过，昨天宣布的8个名人牌匾，现有业主均已同意接受。市府将从下周起，前往市区各处建牌匾。

本文 来 自 家 园 网

去年6小说家诗人立牌匾

本文 来 自 家 园 网

市府祖裔部官员表示，他们的牌匾项目从去年开始，去年为本市6名著名小说家和诗人建了牌匾。明年多市的这个项目将向在各行各业有成就的市民扩大。

家园温哥华,vancouver.iask.

Nicole Arbour: 2011 J. Tuzo Wilson Lecture: Offshore gas hydrates

Prof. Edwards' talk focused principally on the need for good, reliable gas hydrate detection techniques. Methane hydrates (also called methane clathrates) consist of methane gas trapped in crystalline water, resulting in a soft, yellowish solid not unlike ice cream. They are only stable at relatively high pressures and low temperatures, and so are found on and just below the sea floor. They are of considerable interest to researchers because methane is a potent greenhouse gas - if sea temperatures rise too much due to climate change, the clathrates could collapse and release their methane into the atmosphere in a runaway feedback loop. It may also be possible to capture the methane and use it as a fuel (ideally on-site, sequestering the CO produced back into the clathrates) - there is thought to be more carbon locked away in gas hydrates than in all other sources combined. This is where Prof. Edwards' research comes in, as estimates for just how much hydrates there are vary by about a factor of 100.

Resource exploration outfits generally use seismic techniques to survey the sea floor and work out what might be there, but these methods cannot reliably detect gas hydrates. Prof. Edwards' team uses a towed array to transmit an electromagnetic signal along the sea floor, and analyses the extent of electromagnetic diffusion to work out the resistivity of the different layers there. Electromagnetic signals travel fastest in layers containing gas hydrate, slower in normal sediment layers and slowest in sea water, allowing the detection and mapping of hydrate deposits. They tend to occur around subduction zones , where bacteria-produced methane is relased near the sea floor.

To close his lecture with a bit of showmanship, Prof. Edwards produced an actual methane clathrate sample, about the size of a lemon. A robotic submersible working on the sea floor at a depth of about 1.2 km had stirred an area of clathrate up, and the pieces had floated to the surface. A member of Prof. Edwards' research team had then scooped them up with a net and preserved them in liquid nitrogen for later study, the sample in front of us being one of the pieces. After waiting a few minutes for the ice to warm up a little, Prof. Edwards unceremoniously set it on fire with a barbecue lighter, to general applause.

Prof. Edwards' team is currently researching the Bullseye gas vent (off the coast of Vancouver Island) with NEPTUNE Canada , a regional-scale underwater observatory network.

Continents adrift, readings from Scientific American edited by J. Tuzo Wilson

Nares Strait and the drift of Greenland: a conflict in plate tectonics

The Continental crust and its mineral deposits, the proceedings of a symposium held in honour of J. Tuzo Wilson, held at Toronto, May 1979

Hawai'i Volcanoes National Park, Adventure, Explore, Discover

LANGUAGE OF THE EARTH