The Strait of Juan de Fuca is a body of water about 96 miles long that is the Salish Sea's main outlet to the Pacific Ocean. The international boundary between Canada and the United States runs down the centre of the Strait.
The Juan de Fuca Plate is a small tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American Plate at the Cascadia subduction zone. It is named after the explorer of the same name. One of the smallest of Earth's tectonic plates, the Juan de Fuca Plate is a remnant part of the once-vast Farallon Plate, which is now largely subducted underneath the North American Plate.
The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26, 1700, with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers, with an average slip of 20 meters (66 ft).
A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean.
The Cascadia subduction zone is a 960 km fault at a convergent plate boundary, about 112-160 km off the Pacific Shore, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30m. The Oregon Department of Emergency Management estimates shaking would last 5-7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
A submarine canyon is a steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km (3 mi), from canyon floor to canyon rim, as with the Great Bahama Canyon. Just as above-sea-level canyons serve as channels for the flow of water across land, submarine canyons serve as channels for the flow of turbidity currents across the seafloor. Turbidity currents are flows of dense, sediment laden waters that are supplied by rivers, or generated on the seabed by storms, submarine landslides, earthquakes, and other soil disturbances. Turbidity currents travel down slope at great speed, eroding the continental slope and finally depositing sediment onto the abyssal plain, where the particles settle out.
A turbidity current is most typically an underwater current of usually rapidly moving, sediment-laden water moving down a slope; although current research (2018) indicates that water-saturated sediment may be the primary actor in the process. Turbidity currents can also occur in other fluids besides water.
The Olympic Coast National Marine Sanctuary is one of 15 marine sanctuaries administered by the National Oceanic and Atmospheric Administration (NOAA), an agency of the U.S. Department of Commerce. Declared in 1994, the sanctuary encompasses 3,189 square miles (8,260 km2) of the Pacific Ocean along the Olympic Peninsula of Washington state, from Cape Flattery in the north, to the mouth of the Copalis River, a distance of about 162.5 miles (261.5 km). Extending 25 to 40 miles from the shore, it includes most of the continental shelf, as well as parts of three important submarine canyons, the Nitinat Canyon, the Quinault Canyon and the Juan de Fuca Canyon. For 64 miles (103 km) along the coast, the sanctuary shares stewardship with the Olympic National Park. Sanctuary stewardship is also shared with the Hoh, Quileute, and Makah Tribes, as well as the Quinault Indian Nation. The sanctuary overlays the Flattery Rocks, Quillayute Needles, and Copalis Rock National Wildlife Refuges.
Cape Flattery is the northwesternmost point of the contiguous United States. It is in Clallam County, Washington on the Olympic Peninsula, where the Strait of Juan de Fuca joins the Pacific Ocean. It is also part of the Makah Reservation, and is the northern boundary of the Olympic Coast National Marine Sanctuary. Cape Flattery can be reached from a short hike, most of which is boardwalked. The westernmost point in the contiguous United States is at Cape Alava, south of Cape Flattery in Olympic National Park. However, the westernmost tip of Cape Flattery is almost exactly as far west as Cape Alava, the difference being approximately 5 seconds of longitude, about 360 feet (110 m), at high tide and somewhat more at low tide.
The Salish Sea is a marginal sea of the Pacific Ocean located in the Canadian province of British Columbia and the U.S. state of Washington. It includes the Strait of Georgia, the Strait of Juan de Fuca, Puget Sound, and an intricate network of connecting channels and adjoining waterways.
The Blanco Fracture Zone or Blanco Transform Fault Zone (BTFZ) is a right lateral transform fault zone, which runs northwest off the coast of Oregon in the Pacific Northwest of the United States, extending from the Gorda Ridge in the south to the Juan de Fuca Ridge in the north.
The Juan de Fuca Ridge is a mid-ocean spreading center and divergent plate boundary located off the coast of the Pacific Northwest region of North America. The ridge separates the Pacific Plate to the west and the Juan de Fuca Plate to the east. It runs generally northward, with a length of approximately 500 kilometres (310 mi). The ridge is a section of what remains from the larger Pacific-Farallon Ridge which used to be the primary spreading center of this region, driving the Farallon Plate underneath the North American Plate through the process of plate tectonics. Today, the Juan de Fuca Ridge pushes the Juan de Fuca Plate underneath the North American plate, forming the Cascadia Subduction Zone.
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 Quinault Treaty was a treaty agreement between the United States and the Native American Quinault and Quileute tribes located in the western Olympic Peninsula north of Grays Harbor, in the recently formed Washington Territory. The treaty was signed on 1 July 1855, at the Quinault River, and on 25 January 1856 at Olympia, the territorial capital. It was ratified by Congress on 8 March 1859, and proclaimed law on April 11, 1859.
Ocean Networks Canada is a world-leading research and ocean observing facility hosted and owned by the University of Victoria, and managed by the not-for profit ONC Society. ONC operates unparalleled observatories in the deep ocean and coastal waters of Canada’s three coasts–the Arctic, the Pacific and the Atlantic–gathering biological, chemical, geological and physical data to drive solutions for science, industry and society. ONC operates the NEPTUNE and VENUS cabled ocean observatories in the northeast Pacific Ocean and the Salish Sea. Additionally, Ocean Networks Canada operates smaller community-based observatories offshore from Cambridge Bay, Nunavut., Campbell River, Kitamaat Village and Digby Island. These observatories collect data on physical, chemical, biological, and geological aspects of the ocean over long time periods. As with other ocean observatories such as ESONET, Ocean Observatories Initiative, MACHO and DONET, scientific instruments connected to Ocean Networks Canada are operated remotely and provide continuous streams of freely available data to researchers and the public. Over 200 gigabytes of data are collected every day.
The Kaikōura Canyon is a geologically active submarine canyon located southwest of the Kaikōura Peninsula off the northeastern coast of the South Island of New Zealand. It is 60 kilometres (37 mi) long, and is generally U-shaped. The canyon descends into deep water and merges into an ocean channel system that can be traced for hundreds of kilometres across the deep ocean floor. At the head of the Kaikōura Canyon, the depth of water is around 30 metres (98 ft), but it drops rapidly to 600 metres (2,000 ft) and continues down to around 2,000 metres (6,600 ft) deep where it meets the Hikurangi Channel. Sperm whales can be seen close to the coast south of Goose Bay, because the deep water of the Kaikōura Canyon is only one kilometre (0.62 mi) off the shoreline in this area.
