www.earthquakecountry.info/10.5/MajorMovieMisconceptions -> www.earthquakecountry.info/10.5/MajorMovieMisconceptions/
These errors are followed by a brief explanation about why they are wrong. Throughout the explanations you will find underlined words. The first time a glossary term is used (within each explanation), there will be a link to the definition of that term. This occurred on a fault that is almost 1,000 miles (1600 kilometers) long. The earthquake 36 ruptured along the entire length of the fault. This earthquake ruptured 620 miles (1,000 km) of the Alaska-Aleutian fault megathrust, which is 2240 miles (3600 km) long. The longest rupture on the San Andreas Fault was 250 miles (400 km) during the 1906 earthquake. This means that the land west of the San Andreas 40 fault is sliding northwest past the rest of the United States, towards San Francisco. This sliding does not create any space between the two plates for water to fill in. Just like if you rub your hands together, your hands are sliding past each other, but there is no space opening up in between them. In fact, because there is a bend in the San Andreas Fault, the land on both sides of the fault (at the bend) are actually converging and getting closer together. This is what caused the formation of the Transverse Ranges, mountains to the northeast of the Los Angeles basin. Independent of plate motion, Barstow is at an elevation of over 2100 feet (640 meters). This means that the ocean water would have to travel significantly uphill to even reach Barstow. So there will be no oceanfront property in Barstow or anywhere else in central California. But unfortunately for principled writers, gaping faults exist only in movies and novels. The ground moves across a fault during an earthquake, not away from it. Shallow crevasses can form during earthquake-induced landslides, lateral spreads, or other types of ground failures. The faults do not know where the train tracks are, nor do they care when they are rupturing. The only difference is that they occur after a larger earthquake instead of by themselves. You cannot tell from looking at a 49 seismogram if an earthquake is a mainshock or an aftershock, because they look the same. Aftershocks are earthquakes that follow the largest shock of an earthquake sequence. They are smaller than the mainshock (the biggest earthquake) and close to the mainshock fault. Aftershocks can continue over a period of weeks, months, or years. In general, the larger the mainshock, the larger and more numerous the aftershocks, and the longer they will continue. After a major earthquake you should expect to experience periodic shaking from aftershocks. The point on the surface of the Earth directly above the hypocenter is called the epicenter. All earthquakes have epicenters, even aftershocks, since they are just smaller earthquakes occurring as the result of a larger earthquake, or mainshock. Earthquakes begin many kilometers below the region affected by surface weather. People tend to notice earthquakes that fit the pattern and forget the ones that don't. Also, every region of the world has a story about earthquake weather, but the type of weather is whatever they had for their most memorable earthquake. So no earthquakes, including 54 subduction zone earthquakes, can be caused by recent wet weather. FACT: An enduring 56 earthquake image of California is a collapsed adobe home with the doorframe as the only standing part. From this came our belief that a doorway is the safest place to be during an earthquake. In modern houses, doorways are no stronger than any other part of the house and usually have doors that will swing and can injure you. Earthquakes are part of a global tectonic process that generally occurs well beyond the influence or control of humans. The scale and force necessary to produce earthquakes are well beyond our daily lives. The friction caused by movements along a fault can cause the rocks to get so hot they melt. This sounds like a lot of small earthquakes, but there are never enough small ones to eliminate the occasional large event. It would take 32 magnitude 5's, 1000 magnitude 4's, or 32,000 magnitude 3's to equal the energy of one magnitude 6 event. So, even though we always record many more small events than large ones, there are never enough to eliminate the need for the occasional large earthquake. As for "lubricating" faults with water or some other substance, injecting high- pressure fluids deep into the ground is known to be able to trigger earthquakes to occur sooner than would have been the case without the injection. However this would be a dangerous pursuit in any populated area, as one might trigger a damaging earthquake. While earthquakes that occur on strike-slip 67 faults can cause great damage, they rarely generate earthquakes larger than a 68 magnitude 7, and almost never have earthquakes larger than a magnitude 8. This is because subduction zone earthquakes occur along faults, which are much longer and go deeper into the earth than transform boundary faults. This results in more motion during an earthquake along a subduction zone fault. Washington is located above a subduction zone and therefore has the potential to have much larger earthquakes than the transform boundary in California. Great earthquakes associated with circum-Pacific subduction dominate the recent energy release. Sykes, Seismic moment catalog of large shallow earthquakes, 1900 to 1989, Bull. It is interesting to note that in the movie, the Space Needle falls on a completely intact unreinforced brick building. Unlike the Space Needle, brick buildings do very poorly in earthquakes. A brick building would have collapsed long before the Space Needle. The Golden Gate Bridge: Structures the size of the Golden Gate, such as other large bridges or off-shore platforms, typically have a very long natural period of vibration. This tends to reduce the response the structure experiences from the more rapid motions of an earthquake. In the case of the Golden Gate Bridge, one of these challenges is to connect its various large-scale components together, such as the approach bridge structures at the north and south ends to the main bridge structure. Necessary 71 retrofits have been completed or are underway in Phases 1 and 2 of the overall seismic upgrade project for the approaches at the north and south ends. The third phase will tackle some weak points in the suspension bridge itself, especially in the manner in which the deck is connected to the towers. The complete seismic retrofit program is budgeted to cost approximately $400 million. We use several different formulas to determine the magnitude. Most formulas depend on a measure of the shear, or 75 S-waves, which have the largest amplitude and carry most of the seismic wave energy. S-waves travel more slowly than the 76 P-waves used to locate the 77 earthquake, at about 2 to 3 miles/second, so a particular magnitude may not be available until a few minutes after the earthquake. In contrast, the location of the 78 hypocenter is available within a minute of less after the earthquake. In a region of 81 intensity VII 82 (explanation of Modified Mercalli Scale of Intensity) people have difficulty standing, and at VII drivers have trouble steering. Most earthquakes stop happening at depths of about 20 km because the rock is too hot. The asthenosphere begins at about 100 km into the earth. The rock on one side of the 86 fault is being pushed, pulled or slid in the opposite direction as the rock on the other side of the fault. Because of friction, the rock doesn't move right away (just like when you start pushing a really heavy box it doesn't move right away). Eventually, the force pushing the rocks is bigger than the force of friction and the rocks move - this is an earthquake. When the rocks are hotter, there is less friction, and the rocks are easier to move. When the rocks get hot enough, the friction is less that the forces pushing the rocks. When this happens, the rocks slide past each other easily, without causing earthquakes. An exception to really deep earthquakes An exception to the depth limitation is in 87 subduction zones. In a subduction zone, a cold piece of oceanic crust is being pushed underneath other cru...
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