The Timiskaming Graben is a 400 km (250 mi) long and 50 km (31 mi) wide depression straddling the Ontario–Quebec border in Eastern Canada. It is a northwesterly extension of the Ottawa-Bonnechere Graben, a failed arm of the Saint Lawrence rift system which is related to the opening of the Iapetus Ocean.
Formation of the Timiskaming Graben corresponded with collapse of the regional crust along the Quinze Dam and Cross Lake faults possibly as early as 2.4 billion years ago. It was then reactivated during periods of crustal extension related to the breakups of supercontinents Rodinia and Pangaea and during compression related to the various orogenies that formed the Appalachian Mountains. The Timiskaming Graben is now partially filled by Lake Timiskaming, a 100 km (62 mi) long successor to the much larger glacial Lake Barlow which drained at the end of the last glacial period about 8,000 years ago.
The Timiskaming Graben is a seismically active structure in the Western Quebec Seismic Zone.Reactivation of faults has resulted in earthquakes, such as the 1935 Timiskaming earthquake.
In geology, a graben is a depressed block of the crust of a planet bordered by parallel faults.
An aulacogen is a failed arm of a triple junction. Aulacogens are a part of plate tectonics where oceanic and continental crust is continuously being created, destroyed, and rearranged on the Earth’s surface. Specifically, aulacogens are a rift zone, where new crust is formed, that is no longer active.
A rift valley is a linear shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. A rift valley is formed on a divergent plate boundary, a crustal extension or spreading apart of the surface, which is subsequently further deepened by the forces of erosion. When the tensional forces are strong enough to cause the plate to split apart, a center block drops between the two blocks at its flanks, forming a graben. The drop of the center creates the nearly parallel steeply dipping walls of a rift valley when it is new. That feature is the beginning of the rift valley, but as the process continues, the valley widens, until it becomes a large basin that fills with sediment from the rift walls and the surrounding area. One of the best known examples of this process is the East African Rift. On Earth, rifts can occur at all elevations, from the sea floor to plateaus and mountain ranges in continental crust or in oceanic crust. They are often associated with a number of adjoining subsidiary or co-extensive valleys, which are typically considered part of the principal rift valley geologically.
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics.
Lake Timiskaming or Lake Temiskaming is a large freshwater lake on the provincial boundary between Ontario and Quebec, Canada. The lake, which forms part of the Ottawa River, is 110 kilometres (68 mi) in length and covers an area of almost 295 km2 (114 sq mi). Its water level ranges between 175 m (574 ft) and 179 m (587 ft) above sea-level, with a mean annual average of 178.4 m (585 ft). The lake is in places up to 216 m (709 ft) deep. There are several islands on the lake, notably Mann and du Collège Islands.
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America. This belt of volcanoes extends roughly north-northwest from northwestern British Columbia and the Alaska Panhandle through Yukon to the Southeast Fairbanks Census Area of far eastern Alaska, in a corridor hundreds of kilometres wide. It is the most recently defined volcanic province in the Western Cordillera. It has formed due to extensional cracking of the North American continent—similar to other on-land extensional volcanic zones, including the Basin and Range Province and the East African Rift. Although taking its name from the Western Cordillera, this term is a geologic grouping rather than a geographic one. The southmost part of the NCVP has more, and larger, volcanoes than does the rest of the NCVP; further north it is less clearly delineated, describing a large arch that sways westward through central Yukon.
The Saint Lawrence rift system is a seismically active zone paralleling the Saint Lawrence River. The rift system trends northeast and southwest and forms a half-graben that links the Ottawa-Bonnechere and the Saguenay grabens. The rift system extends more than 1,000 km (620 mi) along the Saint Lawrence valley from the Ottawa – Montreal area. Within the system, fault reactivation is believed to occur along late Proterozoic to early Paleozoic normal faults related to the opening of the Iapetus Ocean.
The Ottawa-Bonnechere Graben is a geological structure that coincides with a 55 km (34 mi) wide topographic depression extending from near Montréal through Ottawa. It is part of the St. Lawrence rift system that also includes the seismically active Saguenay graben. This rift valley was formed when the Earth's crust moved downward about a kilometre between two major fault zones known as the Mattawa and Petawawa faults. The length of the graben is about 700 km (435 mi).
The 1935 Temiskamingue earthquake occurred on November 1 with a moment magnitude of 6.1 and a maximum Mercalli intensity of VII. The event took place in the Western Quebec Seismic Zone in the Abitibi-Témiscamingue region of Quebec.
The Baikal Rift Zone is a series of continental rifts centered beneath Lake Baikal in southeastern Russia. Current strain in the rifts tends to be extending with some shear movement. A series of basins form along the zone for more than 2,000 kilometres (1,200 mi), creating a rift valley. The rifts form between the Eurasian Plate to the west and the Amur Plate to the east.
The Upper Rhine Plain, Rhine Rift Valley or Upper Rhine Graben is a major rift, about 350-kilometre-long (220 mi) and on average 50-kilometre-wide (31 mi), between Basel in the south and the cities of Frankfurt/Wiesbaden in the north. Its southern section straddles the France–Germany border. It forms part of the European Cenozoic Rift System, which extends across Central Europe. The Upper Rhine Graben formed during the Oligocene, as a response to the evolution of the Alps to the south. It remains active to the present day. Today, the Rhine Rift Valley forms a downfaulted trough through which the river Rhine flows.
The 2000 Kipawa earthquake struck Quebec and Ontario, Canada with a moment magnitude of 5.2 at 6:22 a.m. on January 1. It occurred in the Western Quebec Seismic Zone. The main shock epicenter was located in Lake Kipawa about 10 km (6 mi) north of Témiscaming in southwestern Quebec and 70 km (43 mi) northeast of North Bay, Ontario. The shaking was strongest within 50 km (31 mi) of the epicenter. It was felt in Témiscaming, North Bay and as far away as Toronto, making it one of the most significant earthquakes in Canada in 2000. The earthquake was triggered by major thrust faults associated with the Ottawa-Bonnechere Graben.
The 1663 Charlevoix earthquake occurred on February 5 in New France, and was assessed to have a moment magnitude of between 7.3 and 7.9. The earthquake occurred at 5:30 p.m. local time and was estimated to have a maximum perceived intensity of X (Extreme) on the Mercalli intensity scale. The main shock epicentre is suggested to have occurred along the Saint Lawrence River, between the mouth of the Malbaie River on the north and the mouth of the Ouelle River on the south. A large portion of eastern North America felt the effects. Landslides and underwater sediment slumps were a primary characteristic of the event with much of the destruction occurring near the epicentral region of the St. Lawrence estuary and also in the area of the Saguenay Graben.
The Saguenay Graben is a rift valley or graben in the geological Grenville Province of southern Quebec, Canada. It is an elongated flat-bottomed basin 250 km (155 mi) long and 50 km (31 mi) wide, bounded by normal faults running parallel to its length.
The Western Quebec Seismic Zone is a seismically active area in the Ottawa Valley in Eastern Ontario and Western Quebec. The zone stretches from Montreal to Témiscaming and from Cornwall up along the Laurentian Mountains.
The European Cenozoic Rift System (ECRIS) is a 1,100 km (680 mi) long system of rifts formed in the foreland of the Alps as the lithosphere responded to the effects of the Alpine and Pyrenean orogenies. The system began to form during the Late Eocene and parts, particularly the Upper and Lower Rhine Grabens, remain seismically active today and are responsible for most of the larger earthquakes in Europe, north of the Alps.
Although the eastern United States is not as seismically active as regions near plate boundaries, large and damaging earthquakes do occur there. Furthermore, when these rare eastern U.S. earthquakes occur, the areas affected by them are much larger than for western U.S. earthquakes of the same magnitude. Thus, earthquakes represent at least a moderate hazard to East Coast cities, including New York City and adjacent areas of very high population density.
A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults.
The geological deformation of Iceland is the way that the rocks of the island of Iceland are changing due to tectonic forces. The geological deformation explains the location of earthquakes, volcanoes, fissures, and the shape of the island. Iceland is the largest landmass (102,775 km²) situated on an oceanic ridge. It is an elevated plateau of the sea floor, situated at the crossing of the Mid-Atlantic Ridge and the Greenland-Iceland-Faeroe Ridge. It lies along the oceanic divergent plate boundary of North American Plate and Eurasian Plate. The western part of Iceland sits on the North American Plate and the eastern part sits on the Eurasian Plate. The Reykjanes Ridge of the Mid-Atlantic ridge system in this region crosses the island from southwest and connects to the Kolbeinsey Ridge in the northeast.
The Canadian Arctic Rift System is a major North American geological structure extending from the Labrador Sea in the southeast through Davis Strait, Baffin Bay and the Arctic Archipelago in the northwest. It consists of a series of interconnected rifts that formed during the Paleozoic, Mesozoic and Cenozoic eras. Extensional stresses along the entire length of the rift system have resulted in a variety of tectonic features, including grabens, half-grabens, basins and faults.