The geography of Antarctica is dominated by its south polar location and, thus, by ice. The Antarctic continent, located in the Earth's southern hemisphere, is centered asymmetrically around the South Pole and largely south of the Antarctic Circle. It is washed by the Southern Ocean or, depending on definition, the southern Pacific, Atlantic, and Indian Oceans. It has an area of more than 14.2 million km2. Antarctica is the largest ice desert in the world.
The Garibaldi Volcanic Belt is a northwest–southeast trending volcanic chain in the Pacific Ranges of the Coast Mountains that extends from Watts Point in the south to the Ha-Iltzuk Icefield in the north. This chain of volcanoes is located in southwestern British Columbia, Canada. It forms the northernmost segment of the Cascade Volcanic Arc, which includes Mount St. Helens and Mount Baker. Most volcanoes of the Garibaldi chain are dormant stratovolcanoes and subglacial volcanoes that have been eroded by glacial ice. Less common volcanic landforms include cinder cones, volcanic plugs, lava domes and calderas. These diverse formations were created by different styles of volcanic activity, including Peléan and Plinian eruptions.
A subglacial volcano, also known as a glaciovolcano, is a volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava. Today they are most common in Iceland and Antarctica; older formations of this type are found also in British Columbia and Yukon Territory, Canada.
A tuya is a flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet. They are rare worldwide, being confined to regions which were covered by glaciers and had active volcanism during the same period.
Hoodoo Mountain, sometimes referred to as Hoodoo Volcano, is a potentially active stratovolcano in the Northern Interior of British Columbia, Canada. It is located 25 kilometres northeast of the Alaska–British Columbia border on the north side of the Iskut River opposite of the mouth of the Craig River. With a summit elevation of 1,850 metres and a topographic prominence of 900 metres, Hoodoo Mountain is one of many prominent peaks within the Boundary Ranges of the Coast Mountains. Its flat-topped summit is covered by an ice cap more than 100 metres thick and at least 3 kilometres in diameter. Two valley glaciers surrounding the northwestern and northeastern sides of the mountain have retreated significantly over the last hundred years. They both originate from a large icefield to the north and are the sources of two meltwater streams. These streams flow along the western and eastern sides of the volcano before draining into the Iskut River.
Tuya Butte is a tuya in the Tuya Range of north-central British Columbia, Canada. It is a bit less isolated from other ranges than neighbouring Mount Josephine. Some of the other volcanoes in the area include South Tuya, Ash Mountain, and Mathews Tuya.
Ash Mountain is the highest summit in the Tuya Range of the Stikine Ranges in northcentral British Columbia, Canada, located immediately north of High Tuya Lake at the north end of Tuya Mountains Provincial Park. It is one of the six tuyas clustered close to Tuya Lake. The base of the volcano comprises pillow lava and hyaloclastite indicating that the volcano formed beneath ice or under a large lake. The volcano comprises loose debris as well as dikes of basaltic rock that intruded into the volcanic pile. Other tuyas in the area include Tuya Butte, South Tuya and Mathews Tuya, although most of the group of tuyas are unnamed.
Caribou Tuya is a basaltic subglacial mound in far northwestern British Columbia that began eruptive activity under glacial ice during the Fraser glaciation. Like Ash Mountain and South Tuya, sections of the subglacial mound reveal a consistent stratigraphic progression from pillow lavas to hyaloclastite deposits from the base upward. Locally the sections are capped by subaerial basaltic lava flows. Samples of the glassy pillow basalts and hyaloclastites along with crystalline basalt flows were collected at Caribou Tuya. The volcano is believed to have formed and last erupted during the Pleistocene Epoch.
South Tuya, also called Southern Tuya, is a tuya clustered around Tuya Lake in the Northern Cordilleran Volcanic Province in British Columbia, Canada. The base of South Tuya comprises hyaloclastite and pillow lava indicating that the volcano formed beneath a large lake or beneath ice.
Mount Brew is a rounded mountain in southwestern British Columbia, Canada, located 18 km (11 mi) southwest of Whistler in the Pacific Ranges of the Coast Mountains. A public cabin run by the Varsity Outdoor Club, Brew Hut, is located near the summit. The alpine area is a popular destination for hiking in the summer and backcountry ski touring in the winter and spring.
Slag Hill is a subglacial volcano associated with the Mount Cayley volcanic field in British Columbia, Canada. It consists of glassy, augite-phyric basaltic andesite in steep-sided, glassy, finely jointed domes and one small, flat-topped bluff. The finely jointed domes are similar to those of Ember Ridge. There are quench features at Slag Hill, which is suggesting that the volcanic activity was subglacial. Slag Hill was formed throughout the Pleistocene period, but its most recent volcanic activity produced a lava flow on its western lobe that shows no evidence of ice-contact volcanism. This indicates the lava flow was erupted less than 10,000 years ago after the last glacial period.
Wetalth Ridge is an isolated ridge in northern British Columbia, Canada, located 74 km (46 mi) southwest of Tatogga and south of Telegraph Creek. It lies on the southwest side of Little Arctic Lake at the southwest corner of Mount Edziza Provincial Park.
Pillow Ridge is a ridge of the Tahltan Highland in northern British Columbia, Canada, located southeast of Telegraph Creek. It extends northwest from Mount Edziza in Mount Edziza Provincial Park.
Pali Dome is a subglacial volcano in the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is part of the Mount Cayley volcanic field and its elevation is 2,250 m (7,380 ft). For the past 2 million years, the Mount Cayley volcanic field has had interactions between ice and lava which have created some unique landforms and an in-ice drainage system."Pali" comes from the Hawaiian word that means cliff or steep hill, while dome refers to the lava dome, which is when doughy lava flows from a volcanic vent which is usually rounded and flat on top.
A subglacial mound (SUGM) is a type of subglacial volcano. This type of volcano forms when lava erupts beneath a thick glacier or ice sheet. The magma forming these volcanoes was not hot enough to melt a vertical pipe right through the overlying glacial ice, instead forming hyaloclastite and pillow lava deep beneath the glacial ice field. Once the glaciers had retreated, the subglacial volcano would be revealed, with a unique shape as a result of their confinement within glacial ice. They are somewhat rare worldwide, being confined to regions which were formerly covered by continental ice sheets and also had active volcanism during the same period. They are found throughout Iceland, Antarctica and the Canadian province of British Columbia.
Meehaz Mountain is a mountain in the Cassiar Country of the Northern Interior of British Columbia, Canada, located on the north side of the headwaters of Teslin River and to the south of the Atsutla Range. It is a product of subglacial volcanism during the Pleistocene period when this area was covered by thick glacial ice, forming a subglacial volcano that never broke through the overlying glacial ice known as a subglacial mound.
Nuthinaw Mountain is a mountain on the Stikine Plateau in northern British Columbia, Canada, located east of Tutsingale Mountain and 72 km (45 mi) northwest of Dease Lake on the north side of Tachilta Lakes. It is a product of subglacial volcanism during the Pleistocene period when this area was covered by thick glacial ice, forming a subglacial volcano that never broke through the overlying glacial ice known as a subglacial mound.
The volcanic history of the Northern Cordilleran Volcanic Province presents a record of volcanic activity in northwestern British Columbia, central Yukon and the U.S. state of easternmost Alaska. The volcanic activity lies in the northern part of the Western Cordillera of the Pacific Northwest region of North America. Extensional cracking of the North American Plate in this part of North America has existed for millions of years. Continuation of this continental rifting has fed scores of volcanoes throughout the Northern Cordilleran Volcanic Province over at least the past 20 million years and occasionally continued into geologically recent times.
The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii.
The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the MCVF volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, a volcanic peak located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.
