About this quiz: All the questions on this quiz are based on information that can be found at Earth Science: Earthquakes. A seismologist immediately recognizes the nature of such an event by the single frequency contained in the record. To find the magnitude of events, you can look at our recent significant earthquake reports and at the the last 30 days of Canada earthquakes. That level of earthquake activity is not observed. Is there a maximum magnitude for an earthquake? A magnitude 3.8 earthquake was reported at 11:18 a.m. Thursday in Concord, Calif., according to the U.S. Geological Survey. Warnings also alert emergency management officials to take action for the entire tsunami hazard zone. About 5% to 10% of earthquakes in California are followed by a larger one within a week and then are considered a foreshock. This information is analyzed in the weeks and months after the main earthquake and permits scientists to better understand the phenomenon of earthquakes in Canada. Are there certain months of the year that are more seismically active than others? Where can I find information on the world's earthquakes? If the accumulated stress exceeds the strength of the rocks making up these brittle zones, the rocks can break suddenly, releasing the stored energy as an earthquake. Have there been damaging earthquakes in western Canada? Near the surface, freeze and thaw cycles can weaken and break rock due to high water pressure. The sudden and brief period of intense ground shaking. The magnitude of an earthquake is directly proportional to how dangerous it is and the damage it will result in. Cross-bracing (X), mass dampers (large heavy counterweights in the tops of tall buildings), and base-isolators (fitted under buildings to allow rolling without swaying). But it’s hard to gather information about deep earthquakes, so scientists don’t have a solid explanation for what causes them. Submitted by watani on October 17, 2012 - 4:31pm. Shake, rattle, and roll! Some of the world's largest earthquakes have occurred here (see next question). For several hours, or even days, after a strongly felt earthquake, it is quite possible that people may feel more shocks. Rules: 1. Also, if the earthquake was large, other scientists specializing in surface deposits (clay, sand) may join the field survey team. For some examples of damage to typical wood-frame houses during the M=7.3 Vancouver Island earthquake of 1946, click below: Unreinforced masonary structures (those not seismically upgraded) are generally more vulnerable to earthquake damage. The American scientist John Winthrop (1714-1779) was one of the first to make scientific studies of earthquakes and is known as the founder of seismology. It shook more than two-thirds of the United States and was felt in Canada. Spelling Bee Test your spelling acumen. However, I believe the idea with alot of sustainable hard planning and hard work is worth trying. Such ice cracks can sometimes be detected by a seismograph if it is located close to the body of water. After a strong earthquake, some cracks may be seen on the ground or in basements. Earthquakes also occur frequently in the Ottawa and St. Lawrence Valleys, in New Brunswick, and the offshore region to the south of Newfoundland. The Cascadia fault, on which megathrust earthquakes occur, is located mostly offshore, west of Vancouver Island, Washington, and Oregon, although it does extend some distance beneath the Olympic Peninsula of Washington State. The deformation of the crust in a predictable pattern can be detected by very careful geodetic measurements using Global Positioning Satellites, precise levelling, micro-gravity measurements and changing distance measurements using laser technology. A megathrust earthquake in Chile in 1960 was magnitude 9.5, and one in Alaska in 1964 was magnitude 9.2. The last one was 300 years ago. Earthquake populations approximately follow this relationship: log N = a - bM. No! A comprehensive database of more than 32 earthquake quizzes online, test your knowledge with earthquake quiz questions. 1. Why do megathrust earthquakes cause tsunamis? “Energy released by earthquakes on a global scale in the last decade is much more than in the previous 25 to30 years,” he said. According to past earthquakes , one can however draw up some general information for Eastern Canada. A 1933 quake in Long Beach, California, registered 6.3, killed 115 people, and caused $40 million in damage. Of these 4000, only about 50 (1/week) are generally felt. If a magnitude 6.9 earthquake can devastate Kobe, Japan, what would a magnitude 9 megathrust earthquake do to Vancouver? What makes them stop? Speak calmly with family members, especially children about what has just happened, in order to relieve stress. Some of this water may penetrate into cracks in the underlying rock, and sometimes this may trigger small earthquakes under or very near the reservoir. There might be several per day, or only several per week. Earthquake activity is also high in the Cascadia Subduction Zone. You can filter the data shown in various ways, e.g. However, the rates of earthquakes in particular regions, expressed in terms of probabilities, can be usefully estimated. In the short term, this information cannot be used to predict earthquakes. Earthquakes are the sudden violent shaking of the ground. Test your understanding of Earthquakes concepts with Study.com's quick multiple choice quizzes. Moreover, modern buildings must be designed according to national or provincial building code standards, which are intended to minimize the probability of building collapse in major earthquakes. Here, the Juan de Fuca Plate dips below the easterly neighbouring North American plate. The watch area may be upgraded to a warning or advisory - or canceled - based on updated information and analysis. Aftershocks are normal; they show that the earth's crust is readjusting after the main earthquake. All of these events cause incredible damage and destruction to an area. At what magnitude do earthquakes begin to be felt? To calculate magnitude, the amplitude of waves on a seismogram is measured, correcting for the distance between the recording instrument and the earthquake epicentre. The largest earthquake recorded here, with magnitude of 6.9, occured in the Mackenzie Mountains in December, 1985. These vary greatly from one region to another, according to many factors which are poorly understood. Over the years however, it was realized that the magnitude that Richter had defined for California (ML means local magnitude), did not apply to Eastern North America where the seismic waves attenuate differently. Here you can create your own quiz and questions like How often do magnitude 8 earthquakes occur? The Kobe earthquake was right beneath the city and the megathrust earthquake will be about 150 kilometres from Vancouver. They are cryoseisms, also known as frost quakes, and can only be felt close to the body of water from which they originate. The plots are delayed by about 5 minutes which is the time it takes to acquire the data and process it. Earthquakes can range from being very weak — they sometimes can’t be felt at all — to disastrous, leading to loss of lives, inflicting destruction across entire cities and towns, and displacing or disrupting the ground .. Read on as we answer important questions regarding earthquakes, tell you some safety measures to take, and present a few earthquake facts. Furthermore, the principle causes of earthquakes (movement of tectonic plates, volcanoes, etc.) (Again, simply put), quakes generate P waves first that move back-and-forth, and followed by S waves that move with more of a sideways motion. How many global earthquakes occur each year? Take cover under, and hold on to a sturdy desk, a table, or a bed - or stand in a doorframe. Your answers are not being recorded. Although not recorded by seismographs, the largest earthquake ever to strike Canada was undoubtedly the giant megathrust (subduction zone) earthquake of 1700 off the west Coast of Vancouver Island. A pink display indicates that there is no data available for that station at that time. The Intensity scale is designed to describe the effects of an earthquake, at a given place, on natural features, on industrial installations and on human beings. 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