107-694: Port Royal is a town in Jamaica, once the largest and most prosperous city in the Caribbean. Port Royal or Port Royale may also refer to: Port Royal Port Royal is a town located at the end of the Palisadoes , at the mouth of Kingston Harbour , in southeastern Jamaica . Founded in 1494 by the Spanish , it was once the largest and most prosperous city in the Caribbean , functioning as
214-414: A careening wharf at Port Royal and rented a building on the foreshore to serve as a storehouse. From 1675, a resident Naval Officer was appointed to oversee these facilities; however, development was cut short by the 1692 earthquake. After the earthquake, an attempt was made to establish a naval base at Port Antonio instead, but the climate there proved disagreeable. From 1735, Port Royal once more became
321-405: A strumpet 500 to see her naked. They used to buy a pipe of wine, place it in the street, and oblige everyone that passed to drink from it. The taverns of Port Royal were known for their excessive consumption of alcohol such that records even exist of the wild animals of the area partaking in the debauchery. During a passing visit, famous Dutch explorer Jan van Riebeeck is said to have described
428-682: A base of operations. In 1657, as a solution to his defence concerns, Governor Edward D'Oyley invited the Brethren of the Coast to come to Port Royal and make it their home port. The Brethren was a group of pirates descended from cattle-hunting boucaniers [ fr ] (later anglicized to buccaneers), who had turned to piracy after being robbed by the Spanish (and subsequently thrown out of Hispaniola). These pirates concentrated their attacks on Spanish shipping, whose interests were considered
535-426: A covered way leading from it to the careening wharves. The adjacent Port Admiral 's (later Commodore's) House included a watch tower , to counter the threat of privateers . The Yard continued to expand to meet the new requirements of steam-powered vessels : the victualling wharf became a coaling depot in the 1840s, and twenty years later a small engineering complex was built. The Yard continued to expand through to
642-571: A depth of less than 70 km (43 mi) are classified as "shallow-focus" earthquakes, while those with a focal depth between 70 and 300 km (43 and 186 mi) are commonly termed "mid-focus" or "intermediate-depth" earthquakes. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, deep-focus earthquakes may occur at much greater depths (ranging from 300 to 700 km (190 to 430 mi)). These seismically active areas of subduction are known as Wadati–Benioff zones . Deep-focus earthquakes occur at
749-488: A depth where the subducted lithosphere should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep-focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure. Earthquakes often occur in volcanic regions and are caused there, both by tectonic faults and the movement of magma in volcanoes . Such earthquakes can serve as an early warning of volcanic eruptions, as during
856-475: A few exceptions to this: Supershear earthquake ruptures are known to have propagated at speeds greater than the S wave velocity. These have so far all been observed during large strike-slip events. The unusually wide zone of damage caused by the 2001 Kunlun earthquake has been attributed to the effects of the sonic boom developed in such earthquakes. Slow earthquake ruptures travel at unusually low velocities. A particularly dangerous form of slow earthquake
963-568: A floating pier where a cruise ship could dock had been built; the first ship arrived on 20 January 2020. Tourists from a few ships (after the effects of the COVID-19 pandemic have ended) might be beneficial to the town, but "there's still much work to be done if the town will become the 'world-class heritage, environmental and cultural attraction ' " according to a BBC Travel report published in September 2020. Another report that month discussed
1070-458: A particular location in the Earth is the average rate of seismic energy release per unit volume. In its most general sense, the word earthquake is used to describe any seismic event that generates seismic waves. Earthquakes can occur naturally or be induced by human activities, such as mining , fracking , and nuclear tests . The initial point of rupture is called the hypocenter or focus, while
1177-560: A particular location in the Earth is the average rate of seismic energy release per unit volume. One of the most devastating earthquakes in recorded history was the 1556 Shaanxi earthquake , which occurred on 23 January 1556 in Shaanxi , China. More than 830,000 people died. Most houses in the area were yaodongs —dwellings carved out of loess hillsides—and many victims were killed when these structures collapsed. The 1976 Tangshan earthquake , which killed between 240,000 and 655,000 people,
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#17327647388181284-556: A port but now included archaeological and other attractions. In 1981, the Nautical Archaeology Program at Texas A&M University began a 10-year underwater archaeological investigation of the portion of Port Royal that sank underwater during the 17th century. The program focused on an area that had sunk directly into the sea and suffered very little damage. Due to very low oxygen levels, a large amount of organic material could be recovered. The efforts made by
1391-579: A safe haven for pirates, Port Royal became noted as their place of execution . Gallows Point welcomed many to their death, including Charles Vane and Calico Jack , who were hanged in 1720. About five months later, the famous woman pirate Mary Read died in the Jamaican prison in Port Royal. Two years later, 41 pirates met their death in one month. Under British rule the Royal Navy made use of
1498-765: A single rupture) are approximately 1,000 km (620 mi). Examples are the earthquakes in Alaska (1957) , Chile (1960) , and Sumatra (2004) , all in subduction zones. The longest earthquake ruptures on strike-slip faults, like the San Andreas Fault ( 1857 , 1906 ), the North Anatolian Fault in Turkey ( 1939 ), and the Denali Fault in Alaska ( 2002 ), are about half to one third as long as
1605-553: A sludge resembling quicksand. Eyewitness accounts attested to buildings sliding into the water, but it is likely some simply sank straight down into the now unstable layer. Underwater archaeology, some of which can be seen in the National Geographic Channel show Wicked Pirate City , reveals the foundations of building underwater, showing there was subsidence, as do comparisons of post-earthquake maps and pre-earthquake maps. Some attempts were made to rebuild
1712-492: A time when many European nations were reluctant to attack the powerful Spanish fleet directly. As a port city, it was notorious for its gaudy displays of wealth and loose morals, with the privateer crews spending their treasure in the many taverns , gambling houses and brothels which catered for the sailors. When the British and Dutch governments officially abandoned the practice of issuing letters of marque to privateers against
1819-408: Is 1,345 millimetres (53 in). The Taino historic indigenous people of the Caribbean occupied this area for centuries before European settlement. They used the area, which they called Caguay or Caguaya , during their fishing expeditions. Although it is not known whether they ever settled at the spot, they did inhabit other parts of Jamaica. The Spanish first landed in Jamaica in 1494 under
1926-525: Is a theory that earthquakes can recur in a regular pattern. Earthquake clustering has been observed, for example, in Parkfield, California where a long-term research study is being conducted around the Parkfield earthquake cluster. An aftershock is an earthquake that occurs after a previous earthquake, the mainshock. Rapid changes of stress between rocks, and the stress from the original earthquake are
2033-524: Is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior. There are three main types of fault, all of which may cause an interplate earthquake : normal, reverse (thrust), and strike-slip. Normal and reverse faulting are examples of dip-slip, where
2140-400: Is divided into 754 Flinn–Engdahl regions (F-E regions), which are based on political and geographical boundaries as well as seismic activity. More active zones are divided into smaller F-E regions whereas less active zones belong to larger F-E regions. Standard reporting of earthquakes includes its magnitude , date and time of occurrence, geographic coordinates of its epicenter , depth of
2247-430: Is frequented by tourists, but is in a state of disrepair. The Jamaican government has recently resolved to further develop the area for its historic and tourist value. This is in part a result of abandonment of plans begun in the early 1960s to develop the town as a cruise ship port and destination. The plans stimulated the archaeological explorations on the site which, in turn, led to the suspension of development solely as
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#17327647388182354-654: Is influenced by tectonic movements along faults, including normal, reverse (thrust), and strike-slip faults, with energy release and rupture dynamics governed by the elastic-rebound theory . Efforts to manage earthquake risks involve prediction, forecasting, and preparedness, including seismic retrofitting and earthquake engineering to design structures that withstand shaking. The cultural impact of earthquakes spans myths, religious beliefs, and modern media, reflecting their profound influence on human societies. Similar seismic phenomena, known as marsquakes and moonquakes , have been observed on other celestial bodies, indicating
2461-545: Is probably a statistical fluctuation rather than a systematic trend. More detailed statistics on the size and frequency of earthquakes is available from the United States Geological Survey. A recent increase in the number of major earthquakes has been noted, which could be explained by a cyclical pattern of periods of intense tectonic activity, interspersed with longer periods of low intensity. However, accurate recordings of earthquakes only began in
2568-423: Is proportional to the area of the fault that ruptures and the stress drop. Therefore, the longer the length and the wider the width of the faulted area, the larger the resulting magnitude. The most important parameter controlling the maximum earthquake magnitude on a fault, however, is not the maximum available length, but the available width because the latter varies by a factor of 20. Along converging plate margins,
2675-410: Is the tsunami earthquake , observed where the relatively low felt intensities, caused by the slow propagation speed of some great earthquakes, fail to alert the population of the neighboring coast, as in the 1896 Sanriku earthquake . During an earthquake, high temperatures can develop at the fault plane, increasing pore pressure and consequently vaporization of the groundwater already contained within
2782-528: The 1907 Kingston earthquake , others by Hurricane Charlie in 1951). A few remain in place, however, including the Naval Hospital complex, some of the steam engineering buildings and a set of officers' houses. There is also a slipway, completed as late as 1904, which (with its accompanying sheds) was designed for housing and launching torpedo boats , stationed there for the Yard's protection. In 2014, it
2889-458: The 1960 Valdivia earthquake in Chile, the largest ever recorded at 9.5 magnitude. Earthquakes result in various effects, such as ground shaking and soil liquefaction , leading to significant damage and loss of life. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami . Earthquakes can trigger landslides . Earthquakes' occurrence
2996-400: The 1980 eruption of Mount St. Helens . Earthquake swarms can serve as markers for the location of the flowing magma throughout the volcanoes. These swarms can be recorded by seismometers and tiltmeters (a device that measures ground slope) and used as sensors to predict imminent or upcoming eruptions. A tectonic earthquake begins as an area of initial slip on the fault surface that forms
3103-587: The 2004 Indian Ocean earthquake is simultaneously one of the deadliest earthquakes in history. Earthquakes that caused the greatest loss of life, while powerful, were deadly because of their proximity to either heavily populated areas or the ocean, where earthquakes often create tsunamis that can devastate communities thousands of kilometers away. Regions most at risk for great loss of life include those where earthquakes are relatively rare but powerful, and poor regions with lax, unenforced, or nonexistent seismic building codes. Tectonic earthquakes occur anywhere on
3210-840: The Admiral of the Royal Navy . The redevelopment plan also includes a five-star hotel . Today, Port Royal is known to post-medieval archaeologists as the "City That Sank". Robert Marx considers it the most important underwater archaeological site in the western hemisphere, yielding 16th–and-17th-century artifacts and many important treasures from indigenous peoples predating its 1518 founding, some from as far away as Guatemala . Several 17th and early 18th century pirate ships sank within Kingston Harbour and are being carefully harvested, under controlled conditions, by various teams of archaeologists. Other "digs" are staked out along various quarters and streets by different teams. By 2019,
3317-499: The Himalayan Mountains . With the rapid growth of mega-cities such as Mexico City, Tokyo, and Tehran in areas of high seismic risk , some seismologists are warning that a single earthquake may claim the lives of up to three million people. While most earthquakes are caused by the movement of the Earth's tectonic plates , human activity can also produce earthquakes. Activities both above ground and below may change
Port Royal (disambiguation) - Misplaced Pages Continue
3424-503: The University of Edinburgh , wrote the quote: "Both opponents and advocates of so-called 'forced trade' declared the town's fortune had the dubious distinction of being founded entirely on the servicing of the privateers' needs and highly lucrative trade in prize commodities.". "A report that the 300 men who accompanied Henry Morgan to Portobello in 1668 returned to the town with a prize to spend of at least £60 each (two or three times
3531-426: The brittle-ductile transition zone and upwards by the ground surface. The mechanics of this process are poorly understood because it is difficult either to recreate such rapid movements in a laboratory or to record seismic waves close to a nucleation zone due to strong ground motion. In most cases, the rupture speed approaches, but does not exceed, the shear wave (S wave) velocity of the surrounding rock. There are
3638-479: The invasion of Jamaica . By 1659 two hundred houses, shops and warehouses had been built around the fort; by 1692 five forts defended the port. The English initially called the place Cagway but soon renamed it Port Royal. For much of the period between the English conquest and the 1692 earthquake , Port Royal served as the unofficial capital of Jamaica, while Spanish Town remained the official capital. In 1872
3745-413: The least principal stress. Strike-slip faulting is intermediate between the other two types described above. This difference in stress regime in the three faulting environments can contribute to differences in stress drop during faulting, which contributes to differences in the radiated energy, regardless of fault dimensions. For every unit increase in magnitude, there is a roughly thirty-fold increase in
3852-406: The lithosphere that creates seismic waves . Earthquakes can range in intensity , from those so weak 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. The seismicity at
3959-408: The 1692 disaster, Port Royal's commercial role was steadily taken over by the rapidly growing nearby town (and later, city) of Kingston. Plans were developed in 1999 to redevelop the small fishing town as a heritage tourism destination to serve cruise ships. The plan was to capitalize on Port Royal's unique and fascinating heritage, with archaeological findings from pre-colonial and privateering years as
4066-553: The 20th century and has been inferred for older anomalous clusters of large earthquakes in the Middle East. It is estimated that around 500,000 earthquakes occur each year, detectable with current instrumentation. About 100,000 of these can be felt. Minor earthquakes occur very frequently around the world in places like California and Alaska in the U.S., as well as in El Salvador, Mexico, Guatemala, Chile, Peru, Indonesia,
4173-433: The 21st century. Seismic waves travel through the Earth's interior and can be recorded by seismometers at great distances. The surface-wave magnitude was developed in the 1950s as a means to measure remote earthquakes and to improve the accuracy for larger events. The moment magnitude scale not only measures the amplitude of the shock but also takes into account the seismic moment (total rupture area, average slip of
4280-399: The Earth's core was located in 1913 by Beno Gutenberg . S waves and later arriving surface waves do most of the damage compared to P waves. P waves squeeze and expand the material in the same direction they are traveling, whereas S waves shake the ground up and down and back and forth. Earthquakes are not only categorized by their magnitude but also by the place where they occur. The world
4387-484: The Earth. Also, the depth of the hypocenter can be computed roughly. P wave speed S waves speed As a consequence, the first waves of a distant earthquake arrive at an observatory via the Earth's mantle. On average, the kilometer distance to the earthquake is the number of seconds between the P- and S wave times 8. Slight deviations are caused by inhomogeneities of subsurface structure. By such analysis of seismograms,
Port Royal (disambiguation) - Misplaced Pages Continue
4494-464: The King's Royal Naval Dockyard. Old Port Royal features a cruise ship pier extending from a reconstructed Chocolata Hole harbour and Fisher's Row, a group of cafes and shops on the waterfront. The King's Royal Naval Dockyard features a combination shipbuilding -museum and underwater aquarium with dioramas for views of the native tropical sealife. The Royal Naval Dockyard also includes the headquarters for
4601-573: The Philippines, Iran, Pakistan, the Azores in Portugal, Turkey, New Zealand, Greece, Italy, India, Nepal, and Japan. Larger earthquakes occur less frequently, the relationship being exponential ; for example, roughly ten times as many earthquakes larger than magnitude 4 occur than earthquakes larger than magnitude 5. In the (low seismicity) United Kingdom, for example, it has been calculated that
4708-424: The Port Royal area. They did, however, retain its Taino name. Spain kept control of Jamaica mostly so that it could prevent other countries from gaining access to the island, which was strategically situated within the trade routes of the Caribbean. Spain maintained control over the island for 146 years, until the English took control following their invasion of 1655. The town was captured by England in 1655 during
4815-557: The Spanish treasure fleets and possessions in South America in the later 16th century, many of the crews turned pirate to allow themselves to maintain their plundering illegally. Port Royal effectively became a pirate republic, and they continued to use the city as their main base during the 17th century. Pirates from around the world congregated at Port Royal, coming from waters as far away as Madagascar . The town became notorious in folklore as 'the wickedest city on Earth'. After
4922-448: The area was nothing but "hot loose sand". According to Mulcahy, "[Modern] scientists and underwater archaeologists now believe that the earthquake was a powerful one and that much of the damage at Port Royal resulted from a process known as liquefaction." Liquefaction occurs when earthquakes strike ground that is loose, sandy, and water-saturated, increasing the water pressure and causing the particles to separate from one another and form
5029-463: The average recurrences are: an earthquake of 3.7–4.6 every year, an earthquake of 4.7–5.5 every 10 years, and an earthquake of 5.6 or larger every 100 years. This is an example of the Gutenberg–Richter law . The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past, but this is because of
5136-531: The basis of possible attractions. Port Royal has a tropical savanna climate ( Köppen climate classification Aw ) with a short dry season from January to April and a lengthy wet season from May to October. Temperatures remain steady throughout the year with the dry season being slightly cooler and range from 25.5 °C (77.9 °F) in January to 27.7 °C (81.9 °F) in May. The average annual precipitation
5243-899: The beginning of the 20th century, but then (with the Admiralty focusing more and more on the situation in Europe ) the Navy withdrew from its station in Jamaica and the Dockyard closed in 1905. (Nevertheless, the Naval Yard and Hospital remained in Admiralty ownership until after the Second World War , with part of the Yard being used by the War Department ). Many of the Dockyard buildings (most of which were of timber construction) were subsequently demolished or destroyed (some in
5350-404: The brittle crust. Thus, earthquakes with magnitudes much larger than 8 are not possible. In addition, there exists a hierarchy of stress levels in the three fault types. Thrust faults are generated by the highest, strike-slip by intermediate, and normal faults by the lowest stress levels. This can easily be understood by considering the direction of the greatest principal stress, the direction of
5457-566: The cause of other earthquakes in the past century. A Columbia University paper suggested that the 8.0 magnitude 2008 Sichuan earthquake was induced by loading from the Zipingpu Dam , though the link has not been conclusively proved. The instrumental scales used to describe the size of an earthquake began with the Richter scale in the 1930s. It is a relatively simple measurement of an event's amplitude, and its use has become minimal in
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#17327647388185564-588: The centre of shipping and commerce in the Caribbean Sea by the latter half of the 17th century. It was destroyed by an earthquake on 7 June 1692 and its accompanying tsunami , leading to the establishment of Kingston , the capital and the most populated and prosperous city in Jamaica. Severe hurricanes have regularly damaged the area. Another severe earthquake occurred in 1907 . Port Royal became home port to English and Dutch government sponsored privateers who were encouraged to attack Spanish vessels, at
5671-440: The city had one drinking house for every 10 residents. In July 1661 alone, 40 new licenses were granted to taverns . During a 20-year period that ended in 1692, nearly 10,000 people lived in Port Royal. In addition to prostitutes and buccaneers, there were four goldsmiths , 44 tavern keepers, and a variety of artisans and merchants who lived in 2,000 buildings crammed into 51 acres (21 ha) of real estate. 213 ships visited
5778-421: The city's population. Disease ran rampant in the next several months, killing an estimated 2,000 additional people. The historical Jamaica earthquake of 7 June 1692 can be dated closely not only by date, but by time of day as well. This is documented by recovery from the sea floor in the 1960s of a pocket watch stopped at 11:43 a.m., recording the time of the devastating earthquake. The earthquake caused
5885-526: The city, starting with the one third that was not submerged, but these met with mixed success and numerous disasters. An initial attempt at rebuilding was again destroyed in 1703 by fire. Subsequent rebuilding was hampered by several hurricanes in the first half of the 18th century, including flooding from the sea in 1722, a further fire in 1750, and a major hurricane in 1774, and soon Kingston eclipsed Port Royal in importance. In 1815, what repairs were being undertaken were destroyed in another major fire, while
5992-558: The city. By the 1660s the city had, for some, become a pirate utopia and had gained a reputation as the " Sodom of the New World" , where most residents were pirates, cutthroats, or prostitutes . When Charles Leslie wrote his history of Jamaica, he included a description of the pirates of Port Royal: Wine and women drained their wealth to such a degree that [...] some of them became reduced to beggary. They have been known to spend 2 or 3,000 pieces of eight in one night; and one gave
6099-529: The dip angle of the rupture plane is very shallow, typically about 10 degrees. Thus, the width of the plane within the top brittle crust of the Earth can reach 50–100 km (31–62 mi) (such as in Japan, 2011 , or in Alaska, 1964 ), making the most powerful earthquakes possible. The majority of tectonic earthquakes originate in the Ring of Fire at depths not exceeding tens of kilometers. Earthquakes occurring at
6206-678: The displacement along the fault is in the direction of dip and where movement on them involves a vertical component. Many earthquakes are caused by movement on faults that have components of both dip-slip and strike-slip; this is known as oblique slip. The topmost, brittle part of the Earth's crust, and the cool slabs of the tectonic plates that are descending into the hot mantle, are the only parts of our planet that can store elastic energy and release it in fault ruptures. Rocks hotter than about 300 °C (572 °F) flow in response to stress; they do not rupture in earthquakes. The maximum observed lengths of ruptures and mapped faults (which may break in
6313-439: The distance from the earthquake and the underlying rock or soil makeup. The first scale for measuring earthquake magnitudes was developed by Charles Francis Richter in 1935. Subsequent scales ( seismic magnitude scales ) have retained a key feature, where each unit represents a ten-fold difference in the amplitude of the ground shaking and a 32-fold difference in energy. Subsequent scales are also adjusted to have approximately
6420-554: The early 1900s, so it is too early to categorically state that this is the case. Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-kilometre-long (25,000 mi), horseshoe-shaped zone called the circum-Pacific seismic belt, known as the Pacific Ring of Fire , which for the most part bounds the Pacific plate . Massive earthquakes tend to occur along other plate boundaries too, such as along
6527-403: The earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane . The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the fault surface that increases the frictional resistance. Most fault surfaces do have such asperities, which leads to a form of stick-slip behavior . Once
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#17327647388186634-426: The earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the North Anatolian Fault in Turkey in
6741-419: The end of the 18th century a small Victualling Yard had been added to the east (prior to this ships had had to go to Kingston and other settlements to take on supplies). At the start of the 19th century, a significant amount of rebuilding took place in what was by now a substantial Royal Navy Dockyard serving the fleet in the Caribbean . A sizeable storehouse with a clocktower formed the centrepiece, with
6848-504: The energy released. For instance, an earthquake of magnitude 6.0 releases approximately 32 times more energy than a 5.0 magnitude earthquake and a 7.0 magnitude earthquake releases 1,000 times more energy than a 5.0 magnitude earthquake. An 8.6-magnitude earthquake releases the same amount of energy as 10,000 atomic bombs of the size used in World War II . This is so because the energy released in an earthquake, and thus its magnitude,
6955-458: The fact that no single earthquake in the sequence is the main shock, so none has a notably higher magnitude than another. An example of an earthquake swarm is the 2004 activity at Yellowstone National Park . In August 2012, a swarm of earthquakes shook Southern California 's Imperial Valley , showing the most recorded activity in the area since the 1970s. Sometimes a series of earthquakes occur in what has been called an earthquake storm , where
7062-462: The fault has locked, continued relative motion between the plates leads to increasing stress and, therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the locked portion of the fault, releasing the stored energy . This energy is released as a combination of radiated elastic strain seismic waves , frictional heating of
7169-411: The fault plane that holds it in place, and fluids can exert a lubricating effect. As thermal overpressurization may provide positive feedback between slip and strength fall at the fault plane, a common opinion is that it may enhance the faulting process instability. After the mainshock, the pressure gradient between the fault plane and the neighboring rock causes a fluid flow that increases pore pressure in
7276-418: The fault surface, and cracking of the rock, thus causing an earthquake. This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory . It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or
7383-541: The fault, and rigidity of the rock). The Japan Meteorological Agency seismic intensity scale , the Medvedev–Sponheuer–Karnik scale , and the Mercalli intensity scale are based on the observed effects and are related to the intensity of shaking. The shaking of the earth is a common phenomenon that has been experienced by humans from the earliest of times. Before the development of strong-motion accelerometers,
7490-420: The focus of the Admiralty's attention. New wharves and storehouses were built at this time, as well as housing for the officers of the Yard. Over the next thirty years, more facilities were added: cooperages , workshops, sawpits , and accommodation (including a canteen) for the crews of ships being careened there. A Royal Naval Hospital was also established on land a little to the west of the Naval Yard; and by
7597-417: The focus. Once the rupture has been initiated, it begins to propagate away from the focus, spreading out along the fault surface. Lateral propagation will continue until either the rupture reaches a barrier, such as the end of a fault segment, or a region on the fault where there is insufficient stress to allow continued rupture. For larger earthquakes, the depth extent of rupture will be constrained downwards by
7704-406: The force that "pushes" the rock mass during the faulting. In the case of normal faults, the rock mass is pushed down in a vertical direction, thus the pushing force ( greatest principal stress) equals the weight of the rock mass itself. In the case of thrusting, the rock mass "escapes" in the direction of the least principal stress, namely upward, lifting the rock mass, and thus, the overburden equals
7811-417: The forts were destroyed, as well; Fort Charles survived, but Forts James and Carlisle sank into the sea, Fort Rupert became a large region of water, and great damage was done to an area known as Morgan's Line. Although the earthquake hit the entire island of Jamaica, the citizens of Port Royal were at a greater risk of death due to the perilous sand, falling buildings, and the tsunami that followed. Though
7918-428: The government designated Kingston , the largest city, as the capital. Port Royal provided a safe harbour initially for privateers and subsequently for pirates plying the shipping lanes to and from Spain and Panama . Buccaneers found Port Royal appealing for several reasons. Its proximity to trade routes allowed them easy access to prey, but the most important advantage was the port's proximity to several of
8025-493: The ground level directly above it is the epicenter . Earthquakes are primarily caused by geological faults , but also by volcanic activity , landslides, and other seismic events. The frequency, type, and size of earthquakes in an area define its seismic activity, reflecting the average rate of seismic energy release. Significant historical earthquakes include the 1556 Shaanxi earthquake in China, with over 830,000 fatalities, and
8132-405: The growth of Port Royal. Merchants and privateers worked together in what is now referred to as "forced trade." Merchants would sponsor trading endeavors with the Spanish, while also sponsoring privateers to attack Spanish ships and rob Spanish coastal towns. While the merchants most certainly had the upper hand, the privateers were an integral part of the operation. Nuala Zahedieh , a lecturer at
8239-410: The intensity of a seismic event was estimated based on the observed effects. Magnitude and intensity are not directly related and calculated using different methods. The magnitude of an earthquake is a single value that describes the size of the earthquake at its source. Intensity is the measure of shaking at different locations around the earthquake. Intensity values vary from place to place, depending on
8346-478: The island of New Providence . Recent genealogical research indicates that Blackbeard and his family moved to Jamaica where Edward Thatch Jr. is listed as being a mariner in the Royal Navy aboard HMS Windsor in 1706. Port Royal benefited from this lively, glamorous infamy and grew to be one of the two largest towns and the most economically important port in the English colonies . At the height of its popularity,
8453-456: The leadership of Christopher Columbus , leading to the destruction of the Taino population. Permanent settlement occurred when Juan de Esquivel brought a group of settlers in 1509. They came in search of new lands and valuable resources, like gold and silver. Instead they began to cultivate and process the sugar cane. Much like the Taino before them, the Spanish did not appear to have much use for
8560-476: The lengths along subducting plate margins, and those along normal faults are even shorter. Normal faults occur mainly in areas where the crust is being extended such as a divergent boundary . Earthquakes associated with normal faults are generally less than magnitude 7. Maximum magnitudes along many normal faults are even more limited because many of them are located along spreading centers, as in Iceland, where
8667-437: The local authorities tried to remove or sink all of the corpses from the water, they were unsuccessful; some simply got away from them, while others were trapped in places that were inaccessible. Improper housing, a lack of medicine or clean water, and the fact that most of the survivors were homeless led to many people dying of malignant fevers. The earthquake and tsunami killed between 1,000 and 3,000 people combined, nearly half
8774-402: The main causes of these aftershocks, along with the crust around the ruptured fault plane as it adjusts to the effects of the mainshock. An aftershock is in the same region as the main shock but always of a smaller magnitude, however, they can still be powerful enough to cause even more damage to buildings that were already previously damaged from the mainshock. If an aftershock is larger than
8881-414: The mainshock, the aftershock is redesignated as the mainshock and the original main shock is redesignated as a foreshock . Aftershocks are formed as the crust around the displaced fault plane adjusts to the effects of the mainshock. Earthquake swarms are sequences of earthquakes striking in a specific area within a short period. They are different from earthquakes followed by a series of aftershocks by
8988-414: The major threat to the town. The English privateers were given letters of marque by Jamaica's governor. Around the same time that pirates were invited to Port Royal, England launched a series of attacks against Spanish shipping vessels and coastal towns. By sending the newly appointed privateers after Spanish ships and settlements, England had successfully set up a system of defence for Port Royal. Spain
9095-654: The only safe passages or straits giving access to the Spanish Main from the Atlantic. The harbour was large enough to accommodate their ships and the shallow waters provided a place to careen and repair these vessels with no difficulty. It was also ideally situated for launching raids on Spanish settlements. From Port Royal, Christopher Myngs sacked Campeche and Henry Morgan attacked Panama, Portobello , and Maracaibo . Additionally, buccaneers Roche Brasiliano , John Davis and Edward Mansvelt used Port Royal as
9202-418: The production of sugar cane. Zahedieh wrote, "The Portobello raid [in 1668] alone produced plunder worth £75,000, more than seven times the annual value of the island’s sugar exports, which at Port Royal prices did not exceed £10,000 at this time." Since the English lacked sufficient troops to prevent either the Spanish or French from seizing it, the Jamaican governors eventually turned to the pirates to defend
9309-527: The program have allowed everyday life in the English colonial port city to be reconstructed in great detail. In 1998, the Port Royal Development Company commissioned architectural firm The Jerde Partnership to create a master plan for the redevelopment of Port Royal, which was completed in 2000. The focus of the plan is a 17th-century-themed attraction that reflects the city's heritage. It has two anchor areas: Old Port Royal and
9416-444: The residents adopted the brick-style homes of their native England. Some urged the population to adopt the low, wooden building style of the previous Spanish inhabitants, but many refused. In the end, all of these separate factors contributed to the impending disaster. On 7 June 1692, a devastating earthquake hit the city causing most of its northern section to be lost – and with it many of the town's houses and other buildings. Many of
9523-530: The rock. In the coseismic phase, such an increase can significantly affect slip evolution and speed, in the post-seismic phase it can control the Aftershock sequence because, after the main event, pore pressure increase slowly propagates into the surrounding fracture network. From the point of view of the Mohr-Coulomb strength theory , an increase in fluid pressure reduces the normal stress acting on
9630-437: The rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, fracking and nuclear tests . An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at
9737-522: The same numeric value within the limits of the scale. Although the mass media commonly reports earthquake magnitudes as "Richter magnitude" or "Richter scale", standard practice by most seismological authorities is to express an earthquake's strength on the moment magnitude scale, which is based on the actual energy released by an earthquake, the static seismic moment. Every earthquake produces different types of seismic waves, which travel through rock with different velocities: Propagation velocity of
9844-448: The sand under Port Royal to liquefy and flow out into Kingston Harbour. The water table was generally only two feet down before the impact, and the town was built on a layer of some 65 feet (20 m) of water-saturated sand. This type of area did not provide a solid foundation on which to build an entire town. Unlike the Spanish before them, the English had decided to settle and develop the small area of land, even while acknowledging that
9951-403: The scenes: The parrots of Port Royal gather to drink from the large stocks of ale with just as much alacrity as the drunks that frequent the taverns that serve it. There is even speculation in pirate folklore that the infamous Blackbeard ( Edward Teach ) met a howler monkey, while at leisure in a Port Royal alehouse, whom he named Jefferson and formed a strong bond with during the expedition to
10058-487: The seaport in 1688. The city's wealth was so great that coins were preferred for payment over the more common system of bartering goods for services. Following Henry Morgan 's appointment as lieutenant governor, Port Royal began to change. Pirates were no longer needed to defend the city. The selling of slaves took on greater importance. Upstanding citizens disliked the reputation the city had acquired. In 1687, Jamaica passed anti-piracy laws. Consequently, instead of being
10165-464: The seismic waves through solid rock ranges from approx. 3 km/s (1.9 mi/s) up to 13 km/s (8.1 mi/s), depending on the density and elasticity of the medium. In the Earth's interior, the shock- or P waves travel much faster than the S waves (approx. relation 1.7:1). The differences in travel time from the epicenter to the observatory are a measure of the distance and can be used to image both sources of earthquakes and structures within
10272-422: The stresses and strains on the crust, including building reservoirs, extracting resources such as coal or oil, and injecting fluids underground for waste disposal or fracking . Most of these earthquakes have small magnitudes. The 5.7 magnitude 2011 Oklahoma earthquake is thought to have been caused by disposing wastewater from oil production into injection wells , and studies point to the state's oil industry as
10379-490: The surrounding fracture networks; such an increase may trigger new faulting processes by reactivating adjacent faults, giving rise to aftershocks. Analogously, artificial pore pressure increase, by fluid injection in Earth's crust, may induce seismicity . Tides may trigger some seismicity . Most earthquakes form part of a sequence, related to each other in terms of location and time. Most earthquake clusters consist of small tremors that cause little to no damage, but there
10486-443: The thickness of the brittle layer is only about six kilometres (3.7 mi). Reverse faults occur in areas where the crust is being shortened such as at a convergent boundary . Reverse faults, particularly those along convergent boundaries, are associated with the most powerful earthquakes (called megathrust earthquakes ) including almost all of those of magnitude 8 or more. Megathrust earthquakes are responsible for about 90% of
10593-461: The total seismic moment released worldwide. Strike-slip faults are steep structures where the two sides of the fault slip horizontally past each other; transform boundaries are a particular type of strike-slip fault. Strike-slip faults, particularly continental transforms , can produce major earthquakes up to about magnitude 8. Strike-slip faults tend to be oriented near vertically, resulting in an approximate width of 10 km (6.2 mi) within
10700-505: The universality of such events beyond Earth. An earthquake is the shaking of the surface of Earth resulting from a sudden release of energy in the lithosphere that creates seismic waves . Earthquakes may also be referred to as quakes , tremors , or temblors . The word tremor is also used for non-earthquake seismic rumbling . In its most general sense, an earthquake is any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by
10807-458: The usual annual plantation wage) leaves little doubt that they were right". The forced trade became almost a way of life in Port Royal. Michael Pawson and David Busseret wrote "...one way or the other nearly all the propertied inhabitants of Port Royal seem to have an interest in privateering." Forced trade was rapidly making Port Royal one of the wealthiest communities in the English territories of North America, far surpassing any profit made from
10914-436: The vast improvement in instrumentation, rather than an increase in the number of earthquakes. The United States Geological Survey (USGS) estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0–7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable. In recent years, the number of major earthquakes per year has decreased, though this
11021-424: The well-funded Living Heritage Programme, which was seeking "to transform the town into a SMART, safe and secure community with a vibrant local economy, preserved cultural heritage and protected natural environment". Earthquake An earthquake – also called a quake , tremor , or temblor – is the shaking of the Earth 's surface resulting from a sudden release of energy in
11128-490: The whole island was severely affected by an epidemic of cholera in 1850. A devastating earthquake on 14 January 1907 liquefied the sand spit, destroying nearly all of the rebuilt city, submerging additional portions, and tilting The Giddy House , an artillery storage room built c. 1880 that is today a minor tourist attraction. Today, the area is a shadow of its former self with a population of fewer than 2,000 that has little to no commercial or political importance. The area
11235-561: Was announced that some of the Historic Naval Hospital buildings would be restored to house a museum as part of a broader Port Royal Heritage Tourism Project. The town grew rapidly, reaching a population of around 6,500 people and approximately 2,000 dwellings, by 1692. As land on which to build diminished, it became common practice to either fill in areas of water and build new infrastructure on top of it, or simply build buildings taller. Buildings gradually became heavier as
11342-450: Was forced to continually defend their possessions from attack, providing them with no opportunity and no means with which to attempt to retake the land. Spain was unable to retake the island and, due to the privateers, could no longer regularly provide their colonies in the New World with manufactured goods. The progressive irregularity of annual Spanish fleets, combined with an increasing demand by colonies for manufactured goods, stimulated
11449-641: Was the deadliest of the 20th century. The 1960 Chilean earthquake is the largest earthquake that has been measured on a seismograph, reaching 9.5 magnitude on 22 May 1960. Its epicenter was near Cañete, Chile. The energy released was approximately twice that of the next most powerful earthquake, the Good Friday earthquake (27 March 1964), which was centered in Prince William Sound , Alaska. The ten largest recorded earthquakes have all been megathrust earthquakes ; however, of these ten, only
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