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Saint Lawrence Rift System
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 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. Two significant historically active seismic zones occur along this system associated with northwest trending intersecting graben structures. The Charlevoix region has been the location of at least five magnitude six or larger earthquakes over the last 350 years, including the 1925 Charlevoix–Kamouraska earthquake. At the Lower St Lawrence zone the largest recorded earthquakes are about magnitude five. Seismic studies indicate a crustal convergence across the Saint Lawrence valley of about per ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismology
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic, atmospheric, and artificial processes such as explosions. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time is called a seismogram. A seismologist is a scientist who does research in seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletus (c. 585 BCE), Anaximenes of Miletus (c. 550 BCE), Aristotle (c. 340 BCE), and Zha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graben
In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic context by Eduard Suess in 1883. The plural form is either ''graben'' or ''grabens''. Formation A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward. Graben often occur side by side with horsts. Horst and graben structures indicate tensional forces and crustal stretching. Graben are produced from parallel normal faults, where the displacement of the hanging wall is downward, while that of the footwall is upward. The faults typically dip toward the center of the graben from both sides. Horsts are parallel blocks that remain between graben; the bounding faults of a horst typically dip away from the center line of the horst. Single or multiple graben can produce a rift valley. Half-g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Geology
Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover information about the history of deformation (strain) in the rocks, and ultimately, to understand the stress field that resulted in the observed strain and geometries. This understanding of the dynamics of the stress field can be linked to important events in the geologic past; a common goal is to understand the structural evolution of a particular area with respect to regionally widespread patterns of rock deformation (e.g., mountain building, rifting) due to plate tectonics. Use and importance The study of geologic structures has been of prime importance in economic geology, both petroleum geology and mining geology. Folded and faulted rock strata commonly form traps that accumulate and concentrate fluids such as petroleum and natural gas. Simil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic Faults Of Canada
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic, atmospheric, and artificial processes such as explosions. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time is called a seismogram. A seismologist is a scientist who does research in seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletus (c. 585 BCE), Anaximenes of Miletus (c. 550 BCE), Aristotle (c. 340 BCE), and Zhan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifts And Grabens
A rift is a geological structure. Rift(s) or The Rift may also refer to: Film and television * ''The Rift'' (1990 film), a film directed by Juan Piquer Simón * ''Rift'' (film), a 2019 Nigerian film directed by Biodun Stephen * Cardiff Rift or The Rift, a fictional wormhole in the ''Doctor Who'' universe Games * ''Rift'' (video game), a 2011 massively multiplayer online role-playing game * ''Rifts'' (role-playing game), 1990 multi-genre role-playing game created by Kevin Siembieda * '' Rifts: Promise of Power'', a 2005 video game * '' Far Gate'', development title ''The Rift'', a 2001 computer game Literature * ''The Rift'' (Allan novel), a 2017 novel by Nina Allan * ''The Rift'' (Williams novel), a 1999 novel by Walter Jon Williams * ''The Rift'' (Star Trek), a 1991 novel by Peter David * '' Avatar: The Last Airbender – The Rift'', a 2014 graphic novel Music * ''Rift'' (album), a 1993 album by Phish * "Rift", a song by Northlane from the 2019 album ''Alien'' * ''Rif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-glacial Rebound
Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound and isostatic depression are phases of glacial isostasy (glacial isostatic adjustment, glacioisostasy), the deformation of the Earth's crust in response to changes in ice mass distribution. The direct raising effects of post-glacial rebound are readily apparent in parts of Northern Eurasia, Northern America, Patagonia, and Antarctica. However, through the processes of ''ocean siphoning'' and ''continental levering'', the effects of post-glacial rebound on sea level are felt globally far from the locations of current and former ice sheets.Milne, G.A., and J.X. Mitrovica (2008) ''Searching for eustasy in deglacial sea-level histories.'' Quaternary Science Reviews. 27:2292–2302. Overview During the last glacial period, much of northern Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charlevoix Impact Structure
The Charlevoix impact structure is a large eroded meteorite impact structure in the Charlevoix region of Quebec, Canada. Only part of the impact structure is exposed at the surface, the rest lying beneath the Saint Lawrence River. Description The original impact structure is estimated to have been in diameter and the age of the impact is estimated to be 450 ± 20 million years (Ordovician to Silurian age).Schmieder, M., Shaulis, B.J., Lapen, T.J., Buchner, E. and Kring, D.A., 2019. ''In situ U–Pb analysis of shocked zircon from the Charlevoix impact structure, Québec, Canada.'' ''Meteoritics & Planetary Science.'' 54(8) pp. 1808-1827. The projectile was probably a stony asteroid, at least in diameter, and weighing an estimated . The Mont des Éboulements, situated in the exact centre of the impact structure, is interpreted as the central uplift, a consequence of elastic rebound.Interpretation Centre, Parc national des Grands-Jardins, Charlevoix The impact structure is class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charlevoix Seismic Zone
The Charlevoix Seismic Zone is a seismically active area in the Charlevoix region of northeastern Quebec, Canada. It is also known as the Charlevoix-Kamouraska Seismic Zone because earthquakes occur in Kamouraska County where the land expression of the seismic zone is separated by the Saint Lawrence River. Much seismic activity takes place under the river. With over 200 small earthquakes occurring each year, the Charlevoix Seismic Zone is one of the most active seismic zones in Canada. Since 1663, five damaging earthquakes have occurred in the area, including a magnitude 7.3-7.9 event in 1663, a magnitude 7.0 event in 1791, a magnitude 6.0 event in 1860, a magnitude 6.5 event in 1870 and a magnitude 6.2 event in 1925. Because of these concerns, the Charlevoix Seismic Zone is considered to be a highly hazardous earthquake zone and it is comparable to those in British Columbia where earthquakes are due to movement of the Earth's tectonic plates. In contrast, the Charlevoix S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1925 Charlevoix–Kamouraska Earthquake
The 1925 Charlevoix–Kamouraska earthquake struck northeastern North America on February 28, reaching 6.2 on the moment magnitude scale. It was one of the most powerful measured in Canada in the 20th century, with a maximum perceived intensity of VIII (''Severe'') on the Mercalli intensity scale at its epicentre in the area of Charlevoix-Kamouraska, Quebec, Kamouraska along the Saint Lawrence River near île aux Lièvres and not greater than VI (''Strong'') in the United States. The quake was felt in Quebec City, Shawinigan, Montreal, as far south as Virginia, and as far west as the Mississippi River. Damage It caused damage in three separate areas. The first had extreme damage constricted to a narrow belt long on both shores of the Saint Lawrence River near the epicentre. In this area, damage at the villages of Baie-Saint-Paul, Saint-Urbain, Quebec, Saint-Urbain, Les Éboulements, Pointe-au-Pic, La Malbaie, Tadoussac and the other nearby villages of Sainte-Anne-de-la-Pocatièr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word ''tremor'' is also used for Episodic tremor and slip, non-earthquake seismic rumbling. At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charlevoix
Charlevoix ( , ) is a cultural and natural region in Quebec, on the north shore of the Saint Lawrence River as well as in the Laurentian Mountains area of the Canadian Shield. This dramatic landscape includes rolling terrain, fjords, headlands, and bays; the region was designated a World Biosphere Reserve by UNESCO in 1989. Administratively, it comprises the Charlevoix and Charlevoix-Est regional county municipalities within the larger Capitale-Nationale administrative region. History The region was named after Pierre François-Xavier de Charlevoix, a French Jesuit explorer and historian who travelled through the area in the 18th century. The community of La Malbaie was known as the first resort area in Canada. As early as 1760, Scottish noblemen Malcolm Fraser and John Nairn hosted visitors at their manors. For much of its history, Charlevoix was home to a thriving summer colony of wealthy Americans, including President William Howard Taft. Geography From an administrative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iapetus Ocean
The Iapetus Ocean (; ) was an ocean that existed in the late Neoproterozoic and early Paleozoic eras of the geologic timescale (between 600 and 400 million years ago). The Iapetus Ocean was situated in the southern hemisphere, between the paleocontinents of Laurentia, Baltica and Avalonia. The ocean disappeared with the Acadian, Caledonian and Taconic orogenies, when these three continents joined to form one big landmass called Euramerica. The "southern" Iapetus Ocean has been proposed to have closed with the Famatinian and Taconic orogenies, meaning a collision between Western Gondwana and Laurentia. Because the Iapetus Ocean was positioned between continental masses that would at a much later time roughly form the opposite shores of the Atlantic Ocean, it can be seen as a sort of precursor of the Atlantic, and the process by which it opened shares many similarities with that of the Atlantic's initial opening in the Jurassic. The Iapetus Ocean was therefore named for the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
