Lac de Gras
Lac de Gras is a lake 300 kilometres north east of Yellowknife, in the Northwest Territories of Canada. Lac de Gras was the centre of the diamond rush of the 1990s. There are two working, one closed, diamond mines in the area, Diavik Diamond Mine, Ekati Diamond Mine, the care and maintenance Snap Lake Diamond Mine, it was called Ekati by aboriginal peoples. The lake is ultraoligotrophic but supports a slow-growing but stable population of some eight species of cold-water fishes, including round whitefish and lake trout. Lake trout dominate the lake, both numerically and in terms of biomass. Other native fish species include common whitefish, Arctic grayling, longnose sucker, slimy sculpin. Diavik Diamond Mines is conducting open-pit mining of kimberlite pipes using explosives near the lake. Lac de Gras' surface area is 56,910.8 ha. The subbasin area is 413,570 ha with the number of lakes smaller than 1 ha 3,487. Lac du Sauvage is a small lake that drains into Lac de Gras through a 45 m wide and 210 m long stream called the Narrows.
The median flood peak discharge in the Narrows is 17.5 m3/s making it an important corridor for fish movements. List of lakes in the Northwest Territories
Provinces and territories of Canada
The provinces and territories of Canada are the sub-national governments within the geographical areas of Canada under the authority of the Canadian Constitution. In the 1867 Canadian Confederation, three provinces of British North America—New Brunswick, Nova Scotia, the Province of Canada —were united to form a federated colony, becoming a sovereign nation in the next century. Over its history, Canada's international borders have changed several times, the country has grown from the original four provinces to the current ten provinces and three territories. Together, the provinces and territories make up the world's second-largest country by area. Several of the provinces were former British colonies, Quebec was a French colony, while others were added as Canada grew; the three territories govern the rest of the area of the former British North America. The major difference between a Canadian province and a territory is that provinces receive their power and authority from the Constitution Act, 1867, whereas territorial governments have powers delegated to them by the Parliament of Canada.
The powers flowing from the Constitution Act are divided between the Government of Canada and the provincial governments to exercise exclusively. A change to the division of powers between the federal government and the provinces requires a constitutional amendment, whereas a similar change affecting the territories can be performed unilaterally by the Parliament of Canada or government. In modern Canadian constitutional theory, the provinces are considered to be sovereign within certain areas based on the divisions of responsibility between the provincial and federal government within the Constitution Act 1867, each province thus has its own representative of the Canadian "Crown", the lieutenant governor; the territories are not sovereign, but instead their authorities and responsibilities come directly from the federal level, as a result, have a commissioner instead of a lieutenant governor. Notes: There are three territories in Canada. Unlike the provinces, the territories of Canada have no inherent sovereignty and have only those powers delegated to them by the federal government.
They include all of mainland Canada north of latitude 60° north and west of Hudson Bay, as well as most islands north of the Canadian mainland. The following table lists the territories in order of precedence. Ontario, New Brunswick, Nova Scotia were the original provinces, formed when several British North American colonies federated on July 1, 1867, into the Dominion of Canada and by stages began accruing the indicia of sovereignty from the United Kingdom. Prior to this and Quebec were united as the Province of Canada. Over the following years, British Columbia, Prince Edward Island were added as provinces; the British Crown had claimed two large areas north-west of the Canadian colony, known as Rupert's Land and the North-Western Territory and assigned them to the Hudson's Bay Company. In 1870, the company relinquished its claims for £300,000, assigning the vast territory to the Government of Canada. Subsequently, the area was re-organized into the province of the Northwest Territories; the Northwest Territories were vast at first, encompassing all of current northern and western Canada, except for the British holdings in the Arctic islands and the Colony of British Columbia.
The British claims to the Arctic islands were transferred to Canada in 1880, adding to the size of the Northwest Territories. The year of 1898 saw the Yukon Territory renamed as Yukon, carved from the parts of the Northwest Territories surrounding the Klondike gold fields. On September 1, 1905, a portion of the Northwest Territories south of the 60th parallel north became the provinces of Alberta and Saskatchewan. In 1912, the boundaries of Quebec and Manitoba were expanded northward: Manitoba's to the 60° parallel, Ontario's to Hudson Bay and Quebec's to encompass the District of Ungava. In 1869, the people of Newfoundland voted to remain a British colony over fears that taxes would increase with Confederation, that the economic policy of the Canadian government would favour mainland industries. In 1907, Newfoundland acquired dominion status. In the middle of the Great Depression in Canada with Newfoundland facing a prolonged period of economic crisis, the legislature turned over political control to the Newfoundland Commission of Government in 1933.
Following Canada's participation in World War II, in a 1948 referendum, a narrow majority of Newfoundland citizens voted to join the Confederation, on March 31, 1949, Newfoundland became Canada's tenth province. In 2001, it was renamed Newfoundland and Labrador. In 1903, the Alaska Panhandle Dispute fixed British Columbia's northwestern boundary; this was one of only two provinces in Canadian history to have its size reduced. The second reduction, in 1927, occurred when a boundary dispute between Canada and the Dominion of Newfoundland saw Labrador increased at Quebec's expense – this land returned to Canada, as part of the province of Newfoundland, in 1949. In 1999, Nunavut was created from the eastern portion of the Northwest Territories. Yukon lies in the western portion of Northern Canada. All t
Advanced Spaceborne Thermal Emission and Reflection Radiometer
The Advanced Spaceborne Thermal Emission and Reflection Radiometer is a Japanese sensor, one of five remote sensory devices on board the Terra satellite launched into Earth orbit by NASA in 1999. The instrument has been collecting data since February 2000. ASTER provides high-resolution images of the planet Earth in 14 different bands of the electromagnetic spectrum, ranging from visible to thermal infrared light; the resolution of images ranges between 90 meters. ASTER data are used to create detailed maps of surface temperature of land, emissivity and elevation. In April 2008, the SWIR detectors of ASTER began malfunctioning and were publicly declared non-operational by NASA in January 2009. All SWIR data collected after 1 April 2008 has been marked as unusable; the ASTER Global Digital Elevation Model is available at no charge to users worldwide via electronic download. As of 2 April 2016, the entire catalogue of ASTER image data became publicly available online at no cost, it can be downloaded with a free registered account from either NASA's Earth Data Search delivery system or from the USGS Earth Explorer delivery system.
On 29 June 2009, the Global Digital Elevation Model was released to the public. A joint operation between NASA and Japan's Ministry of Economy and Industry, the Global Digital Elevation Model is the most complete mapping of the earth made, covering 99% of its surface; the previous most comprehensive map, NASA's Shuttle Radar Topography Mission, covered 80% of the Earth's surface, with a global resolution of 90 meters, a resolution of 30 meters over the USA. The GDEM covers the planet from 83 degrees North to 83 degrees South, becoming the first earth mapping system that provides comprehensive coverage of the polar regions, it was created by compiling 1.3 million VNIR images taken by ASTER using single-pass stereoscopic correlation techniques, with terrain elevation measurements taken globally at 30-meter intervals. Despite the high nominal resolution, some reviewers have commented that the true resolution is lower, not as good as that of SRTM data, serious artifacts are present; some of these limitations have been confirmed by METI and NASA, who point out that the current version of the GDEM product is "research grade".
During October 2011, version 2 of Global Digital Elevation Model was publicly released. This is considered an improvement upon version 1; these improvements include increased horizontal and vertical accuracy, better horizontal resolution, reduced presence of artifacts, more realistic values over water bodies. However, one reviewer still regards the Aster version 2 dataset, although showing'a considerable improvement in the effective level of detail', to still be regarded as'experimental or research grade' due to presence of artefacts. A 2014 study showed that over rugged mountainous terrain the ASTER version 2 data set can be a more accurate representation of the ground than the SRTM elevation model. Ground sample distance Shuttle Radar Topography Mission Official website NASA site on ASTER Official METI ASTER GDEM Site Official NASA ASTER GDEM Site
Snap Lake Diamond Mine
Snap Lake Mine is a remote fly-in/fly-out operation located about 220 km northeast of Yellowknife, Northwest Territories, according to De Beers, was the first De Beers mine outside of Africa. It was Canada's first underground diamond mine. Construction began with the opening of an access winter road in 2005. By the end of 2013, De Beers had spent US$1.8 billion on mine operation. Of that total, De Beers spent US$1.3 billion with Northwest Territories-based contractors and suppliers, including US$723 million with Aboriginal businesses or joint ventures. The mine began commercial production on January 16, 2008 and was opened on July 25, 2008. In 2013, Snap Lake Mine provided 776 person years of employment, including 274 person years of employment to Northwest Territories residents, close to the 300 NWT resident employees predicted during the mine’s environmental assessment. 400 people are working at the mine on any given day. Lifetime of the mine is estimated to be about 15 years. Resource estimates suggest 16.1 million carats over life of mine.
The Snap Lake mine was featured in a television series on The History Channel. The Snap Lake mine was featured on the Canadian Discovery channel show Daily Planet as part of the special feature'Daily Planet Goes North – More Ice for the Arctic'; the mine is served by the Snap Lake Airport, a private airport, for cargo and passengers entering and leaving the remote site. On December 4, 2015, De Beers announced that due to a drop in the market price of diamonds and a necessary costly license exemption they would stop production of diamonds at the Snap Lake Mine, putting it into "care and maintenance" state so that it could be re-opened at a date if so desired. 70 employees would remain on the site as a result, but 434 were laid off. Ekati Diamond Mine Diavik Diamond Mine Volcanism of Northern Canada "Digging for Diamonds 24/7 Under Frozen Snap Lake", November 24, 2008 Photo gallery at De Beers Canada Snap Lake project, gallery at Flickr
Ekati Diamond Mine
The Ekati Diamond Mine is Canada's first surface and underground diamond mine. It is located 310 km north-east of Yellowknife, Northwest Territories, about 200 km south of the Arctic Circle, near Lac de Gras; until 2014 Ekati was a joint venture between Dominion Diamond Mines, the two geologists who discovered kimberlite pipes north of Lac de Gras, Chuck Fipke and Stewart Blusson each holding a 10% stake in the mine, until Fipke sold his share to Dominion. The first volcanic pipe found in the Lac de Gras region was the Point Lake kimberlite, discovered by Chuck Fipke and Stewart Blusson, prospecting in the region for ten years, having found kimberlite indicator minerals as early as 1985; the Point Lake kimberlite was determined to be uneconomic, but its discovery precipitated one of largest staking rushes in mining history, covering most of the area between Yellowknife and the Arctic coast. There are 156 known kimberlite pipes within the Ekati block of claims, including the Point Lake pipe.
Ekati began operations on October 14, 1998, was operated by BHP Billiton Canada Inc. a part of the BHP Billiton Group, the world's largest diversified resources company. The next kimberlites to be developed at Ekati will be mined using open pit methods and are named Jay and Sable, discovered in 1993 and 1995, respectively. Underground mining of the Misery kimberlite will commence in 2020, after open pit operations have been completed. Ekati Diamond mine, operated by Dominion Diamond is scheduled to remain operational until 2033. On November 13, 2012, CBC reported that the Harry Winston Diamond Corporation, 40% owners of Diavik Diamond Mine, would buy Ekati for US$500 million. Diamonds at the Ekati site are found in 45- to 62-million-year-old kimberlite pipes of the Lac de Gras kimberlite field, most of which lie underneath shallow lakes. Between 1998 and 2009, the mine has produced 40 million carats of diamonds out of six open pits; as the high grade ore close to surface was depleted, development was completed to access the ore utilizing underground methods.
There is one underground operation with open-cut mining occurring in Fox Pit. The mine's current annual production is estimated to be 7.5 million carats of diamonds. Ekati supplies rough diamonds to the global market through its sorting and selling operations in Canada and India. Hugo Dummett of BHP, credited as co-discoverer of Ekati Volcanism of Canada Volcanism of Northern Canada Ekati Airport Creaser, R. A. et al. 2004. "Macrocrystal phlogopite Rb-Sr dates for the Ekati property kimberlites, Slave Province, Canada: evidence for multiple intrusive episodes in the Paleocene and Eocene", 8th International Kimberlite Conference Selected Papers, vol. 1, pp. 399–414. Abraham, October 11, 2006. "X marks the spotlight for elusive benefactor", Mail. Stuart Blusson from the GSC to Ekati "EKATI Diamond Mine 2009 Year in Review". BHP Billiton Canada Inc. 2009. Retrieved 2010-06-04.] Kevin Krajick, Barren Lands: An Epic Search for Diamonds in the North American Arctic. 2001, Freeman/Henry Holt, ISBN 0-7167-4026-5.
Review at Smithsonian Magazine Chapter 17. Diamond Exploration – Ekati and Diavik Mines, Canada by Charles J. Moon in Charles J. Moon, M. K. G. Whateley, Anthony M. Evans, Introduction to Mineral Exploration, 2nd Edition. 2006,Wiley-Blackwell. ISBN 978-1-4051-1317-5. Figures and captions from Chapter 17 are available at publisher's site Ekati Diamond Mine photos at Google Images Ekati Diamond Mine profile at BHP Billiton Watch CanadaMark+
The tonne referred to as the metric ton in the United States and Canada, is a non-SI metric unit of mass equal to 1,000 kilograms or one megagram. It is equivalent to 2,204.6 pounds, 1.102 short tons or 0.984 long tons. Although not part of the SI, the tonne is accepted for use with SI units and prefixes by the International Committee for Weights and Measures; the tonne is derived from the weight of 1 cubic metre of pure water. The SI symbol for the tonne is't', adopted at the same time as the unit in 1879, its use is official for the metric ton in the United States, having been adopted by the United States National Institute of Standards and Technology. It is a symbol, not an abbreviation, should not be followed by a period. Use of upper and lower case is significant, use of other letter combinations is not permitted and would lead to ambiguity. For example,'T','MT','Mt','mt' are the SI symbols for the tesla, megatesla and millitonne respectively. If describing TNT equivalent units of energy, this is equivalent to 4.184 petajoules.
In French and most varieties of English, tonne is the correct spelling. It is pronounced the same as ton, but when it is important to clarify that the metric term is meant, rather than short ton, the final "e" can be pronounced, i.e. "tonny". In Australia, it is pronounced. Before metrication in the UK the unit used for most purposes was the Imperial ton of 2,240 pounds avoirdupois or 20 hundredweight, equivalent to 1,016 kg, differing by just 1.6% from the tonne. The UK Weights and Measures Act 1985 explicitly excluded from use for trade certain imperial units, including the ton, unless the item being sold or the weighing equipment being used was weighed or certified prior to 1 December 1980, then only if the buyer was made aware that the weight of the item was measured in imperial units. In the United States metric ton is the name for this unit used and recommended by NIST. Both spellings are acceptable in Canadian usage. Ton and tonne are both derived from a Germanic word in general use in the North Sea area since the Middle Ages to designate a large cask, or tun.
A full tun, standing about a metre high, could weigh a tonne. An English tun of wine weighs a tonne, 954 kg if full of water, a little less for wine; the spelling tonne pre-dates the introduction of the SI in 1960. In the United States, the unit was referred to using the French words millier or tonneau, but these terms are now obsolete; the Imperial and US customary units comparable to the tonne are both spelled ton in English, though they differ in mass. One tonne is equivalent to: Metric/SI: 1 megagram. Equal to 1000000 grams or 1000 kilograms. Megagram, Mg, is the official SI unit. Mg is distinct from milligram. Pounds: Exactly 1000/0.453 592 37 lb, or 2204.622622 lb. US/Short tons: Exactly 1/0.907 184 74 short tons, or 1.102311311 ST. One short ton is 0.90718474 t. Imperial/Long tons: Exactly 1/1.016 046 9088 long tons, or 0.9842065276 LT. One long ton is 1.0160469088 t. For multiples of the tonne, it is more usual to speak of millions of tonnes. Kilotonne and gigatonne are more used for the energy of nuclear explosions and other events in equivalent mass of TNT loosely as approximate figures.
When used in this context, there is little need to distinguish between metric and other tons, the unit is spelt either as ton or tonne with the relevant prefix attached. *The equivalent units columns use the short scale large-number naming system used in most English-language countries, e.g. 1 billion = 1,000 million = 1,000,000,000.†Values in the equivalent short and long tons columns are rounded to five significant figures, see Conversions for exact values.ǂThough non-standard, the symbol "kt" is used for knot, a unit of speed for aircraft and sea-going vessels, should not be confused with kilotonne. A metric ton unit can mean 10 kilograms within metal trading within the US, it traditionally referred to a metric ton of ore containing 1% of metal. The following excerpt from a mining geology textbook describes its usage in the particular case of tungsten: "Tungsten concentrates are traded in metric tonne units (originally designating one tonne of ore containing 1% of WO3, today used to measure WO3 quantities in 10 kg units.
One metric tonne unit of tungsten contains 7.93 kilograms of tungsten." Note that tungsten is known as wolfram and has the atomic symbol W. In the case of uranium, the acronym MTU is sometimes considered to be metric ton of uranium, meaning 1,000 kg. A gigatonne of carbon dioxide equivalent is a unit used by the UN climate change panel, IPCC, to measure the effect of a technolo
North Slave Region
The North Slave Region or Tłicho Region is one of five administrative regions in the Northwest Territories of Canada. It is the most populous of the five regions, with a population of 23,000. According to Municipal and Community Affairs the region consists of eight communities with the regional offices situated in Behchokǫ̀ and Yellowknife. With the exception of Yellowknife the communities are predominantly First Nations; the North Slave Region includes the following communities: ^ a: 2001 estimated population. Included with Yellowknife North Slave Region at Municipal and Community Affairs