Arnaud River
Encyclopedia
The Arnaud River is a river in Nunavik
, Quebec
, Canada
, flowing from the low plateau
x of the Ungava Peninsula
through a series of glacial
lake
s to Ungava Bay
. Its mean discharge is approximately 15 km³ per year, but the river flows only in the summer as it is frozen to several metres for the rest of the year. The total length of the river is about 280 kilometres, but there are several main channels in the upper reaches of the river, most of them unnamed and hardly sighted even by the native Inuit
.
The Inuit village of Kangirsuk
lies near the mouth of the Arnaud River on the north shore of Payne Bay, 13 kilometres (8.1 mi) inland from the western coast of Ungava Bay.
Most of the basin is almost totally barren owing to the harsh climate
- the mean temperature is only about 7°C even at the height of summer and continuous permafrost extends deep from only half a metres below the surface. The only vegetation is low shrubs at the lower levels, for no trees grow within the Arnaud basin even in the most sheltered sites, and the river freezes for too long to make hydroelectric development feasible.
The basin of the Arnaud River, though intensely glaciated for almost the whole of the Quaternary
- ice sheets are known to have been thicker over the basin at the Last Glacial Maximum
than they are over Antarctica today - is the site of a major meteorite impact about a million years ago that has been surprisingly well preserved, probably because the exposed surface rocks are exceedingly old and the meteorite might have been deposited in such a way as to ensure preservation during the long glaciations.
Nunavik
Nunavik comprises the northern third of the province of Quebec, Canada. Covering a land area of 443,684.71 km² north of the 55th parallel, it is the homeland of the Inuit of Quebec...
, Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, flowing from the low plateau
Plateau
In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...
x of the Ungava Peninsula
Ungava Peninsula
The Ungava Peninsula of Nunavik, Quebec, Canada, is bounded by Hudson Bay to the west, Hudson Strait to the north, and Ungava Bay to the east. The Ungava Peninsula is part of the Labrador Peninsula and covers about 252,000 km²...
through a series of glacial
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...
lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s to Ungava Bay
Ungava Bay
Ungava Bay is a large bay in northeastern Canada separating Nunavik from Baffin Island. The bay is shaped like a rounded square with a side length of about and has an area of approximately...
. Its mean discharge is approximately 15 km³ per year, but the river flows only in the summer as it is frozen to several metres for the rest of the year. The total length of the river is about 280 kilometres, but there are several main channels in the upper reaches of the river, most of them unnamed and hardly sighted even by the native Inuit
Inuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...
.
The Inuit village of Kangirsuk
Kangirsuk, Quebec
Kangirsuk is an Inuit village in northern Nunavik, Quebec, Canada. It is north of Kuujjuaq, between Aupaluk and Quaqtaq. The community is only accessible by air and, in late summer, by boat...
lies near the mouth of the Arnaud River on the north shore of Payne Bay, 13 kilometres (8.1 mi) inland from the western coast of Ungava Bay.
Most of the basin is almost totally barren owing to the harsh climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
- the mean temperature is only about 7°C even at the height of summer and continuous permafrost extends deep from only half a metres below the surface. The only vegetation is low shrubs at the lower levels, for no trees grow within the Arnaud basin even in the most sheltered sites, and the river freezes for too long to make hydroelectric development feasible.
The basin of the Arnaud River, though intensely glaciated for almost the whole of the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
- ice sheets are known to have been thicker over the basin at the Last Glacial Maximum
Last Glacial Maximum
The Last Glacial Maximum refers to a period in the Earth's climate history when ice sheets were at their maximum extension, between 26,500 and 19,000–20,000 years ago, marking the peak of the last glacial period. During this time, vast ice sheets covered much of North America, northern Europe and...
than they are over Antarctica today - is the site of a major meteorite impact about a million years ago that has been surprisingly well preserved, probably because the exposed surface rocks are exceedingly old and the meteorite might have been deposited in such a way as to ensure preservation during the long glaciations.