A seamount is a large submarine landform that rises from the ocean floor without reaching the water surface, and thus is not an island, islet, or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to 1,000–4,000 m (3,300–13,100 ft) in height. They are defined by oceanographers as independent features that rise to at least 1,000 m (3,281 ft) above the seafloor, characteristically of conical form. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. After they have subsided and sunk below the sea surface, such flat-top seamounts are called "guyots" or "tablemounts".
The Coast Mountains are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River. The mountain range's name derives from its proximity to the sea coast, and it is often referred to as the Coast Range. The range includes volcanic and non-volcanic mountains and the extensive ice fields of the Pacific and Boundary Ranges, and the northern end of the volcanic system known as the Cascade Volcanoes. The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range, the Insular Mountains, the Olympic Mountains, the Oregon Coast Range, the California Coast Ranges, the Saint Elias Mountains and the Chugach Mountains. The Coast Mountains are also part of the American Cordillera—a Spanish term for an extensive chain of mountain ranges—that consists of an almost continuous sequence of mountain ranges that form the western backbone of North America, Central America, South America and Antarctica.
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars, along with less common volcanic forms such as tuyas and subglacial mounds.
The Explorer Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located about 241 km (150 mi) west of Vancouver Island, British Columbia, Canada. It lies at the northern extremity of the Pacific spreading axis. To its east is the Explorer Plate, which together with the Juan de Fuca Plate and the Gorda Plate to its south, is what remains of the once-vast Farallon Plate which has been largely subducted under the North American Plate. The Explorer Ridge consists of one major segment, the Southern Explorer Ridge, and several smaller segments. It runs northward from the Sovanco Fracture Zone to the Queen Charlotte Triple Junction, a point where it meets the Queen Charlotte Fault and the northern Cascadia subduction zone.
The geology of the Pacific Northwest includes the composition, structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fire: the subduction of the Pacific and Farallon Plates under the North American Plate is responsible for many of the area's scenic features as well as some of its hazards, such as volcanoes, earthquakes, and landslides.
Bowie Seamount, or SG̱aan Ḵinghlas in the Haida language, is a large submarine volcano in the northeastern Pacific Ocean, located 180 km (110 mi) west of Haida Gwaii, British Columbia, Canada. The seamount is also known as Bowie Bank. The English name for the feature is after William Bowie of the United States Coast and Geodetic Survey.
The Tuzo Wilson Seamounts, also called J. Tuzo Wilson Knolls and Tuzo Wilson Knolls, are two young active submarine volcanoes off the coast of British Columbia, Canada, located 200 km (124 mi) northwest of Vancouver Island and south of the Haida Gwaii archipelago The two seamounts are members of the Kodiak-Bowie Seamount chain, rising 500 m (1,640 ft) to 700 m (2,297 ft) above the mean level of the northeastern Pacific Ocean and is a seismically active site southwest of the southern end of the Queen Charlotte Fault. They are named after Canadian geologist John Tuzo Wilson.
The Cobb-Eickelberg seamount chain is a range of undersea mountains formed by volcanic activity of the Cobb hotspot located in the Pacific Ocean. The seamount chain extends to the southeast on the Pacific Plate, beginning at the Aleutian Trench and terminating at Axial Seamount, located on the Juan de Fuca Ridge. The seamount chain is spread over a vast length of approximately 1,800 km. The location of the Cobb hotspot that gives rise to these seamounts is 46° N—130° W. The Pacific plate is moving to the northwest over the hotspot, causing the seamounts in the chain to decrease in age to the southeast. Axial is the youngest seamount and is located approximately 480 km west of Cannon Beach, Oregon. The most studied seamounts that make up this chain are Axial, Brown Bear, Cobb, and Patton seamounts. There are many other seamounts in this chain which have not been explored.
Peirce Seamount, also called Pierce Seamount, is a seamount located in the Pacific Ocean west of the Queen Charlotte Islands, British Columbia, Canada. It lies between Denson Seamount and Hodgkins Seamount and is member of the Kodiak-Bowie Seamount chain, a chain of seamounts in southeastern Gulf of Alaska stretching from the Aleutian Trench in the north to Bowie Seamount in the south.
The following outline is provided as an overview of and introduction to Oceanography.
The Oshawa Seamount is a seamount located in the Pacific Ocean off the coast of Haida Gwaii, British Columbia, Canada.
The Dellwood Seamounts are a seamount range located in the Pacific Ocean northwest of Vancouver Island, British Columbia, Canada. They are also known as the Dellwood Seamount Range or the Dellwood Seamount Chain.
The Tucker Seamount is a seamount located in the Pacific Ocean off the coast of northern Vancouver Island, British Columbia, Canada.
The Chelan Seamount is a seamount located in the Pacific Ocean off the coast of northern Vancouver Island, British Columbia, Canada.
The Seminole Seamount is a seamount located in the Pacific Ocean off the coast of northern Vancouver Island, British Columbia, Canada.
The Union Seamount is a seamount located in the Pacific Ocean off the coast of northern Vancouver Island, British Columbia, Canada.
The Union Seamount is a seamount located in the Pacific Ocean off the coast of northern Vancouver Island, British Columbia, Canada.
The Heck Seamount is a seamount located in the Pacific Ocean off the coast of central Vancouver Island, British Columbia, Canada.
Magic Mountain is a large long-lived hydrothermal vent field on the Southern Explorer Ridge, located about 150 miles west of Vancouver Island, British Columbia, Canada. Unlike most hydrothermal systems found in the Pacific Ocean, Magic Mountain is situated outside the Explorer Ridge. Its source is believed to rise along fault systems.
The Mariana Plate is a micro tectonic plate located west of the Mariana Trench which forms the basement of the Mariana Islands which form part of the Izu–Bonin–Mariana Arc. It is separated from the Philippine Sea Plate to the west by a divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. This eastern subduction is divided into the Mariana Trench, which forms the southeastern boundary, and the Izu–Ogasawara Trench the northeastern boundary. The subduction plate motion is responsible for the shape of the Mariana plate and back arc.
