Thursday, January 16, 2020

Were There Earthquakes and Volcanoes in the Land of Promise?

The most powerful earthquakes on record are so-called subduction earthquakes, called Megathrust earthquakes. These giant quakes are measured in terms of magnitude, which is a number that characterizes the relative size of an earthquake, and measurement of the maximum motion or vibration of the earth. The most powerful earthquake ever recorded took place in Chile in the spring of 1960, referred to as the “Gran Terremoto” with its epicenter in the town of Lumaco, 350-miles south of Santiago, registering 9.6 on the Richter scale. Five other earthquakes in Chile rank in the top ten quakes in the world: Curanilahue at 8.1; Concepción at 8.1; Araucanía at 8.1; Aysén 7.1; and Bio Bio at 7.8.
The old Richter magnitudes that were used for decades, which aren't used anymore, were calculated from ground movements (the amplitudes of seismic waves). So-called moment magnitudes, used since the 1970s, are based on a more complicated formula but were designed to be comparable for most earthquakes.
    In this measurement, the difference of a small number increase is measured by a 10-times greater scale. As an example, an earthquake of magnitude 9 shakes the earth ten times greater than a magnitude 8 quake, and 100 times greater than a magnitude of 7. The difference between a 9.6 and an 8.1 would be approximately 10.5 times greater, or would shake the earth 150 times greater.
    The point is, for a quake to be considered as “there was also a great and terrible tempest; and there was terrible thunder, insomuch that it did shake the whole earth as if it was about to divide asunder” (3 Nephi 8:6); and “there was a more great and terrible destruction in the land northward; for behold, the whole face of the land was changed, because of the tempest and the whirlwinds and the thunderings and the lightnings, and the exceedingly great quaking of the whole earth” (3 Nephi 8:12), it need be greater, stronger, and more destructive than anything experienced before it.
    This does not mean there were no previous storms, lightnings, thunder, whirlwinds, or quakes known in the Land of Promise prior to this event. It means that whatever weathering disasters that had previously occurred, this one was the greatest or more destructive of all. And by a large margin. So large, it should be kept in mind when reading the destruction in 3 Nephi that most, but not all, earthquakes are related to volcanoes. For example, most earthquakes are along the edges of tectonic plates, which is where most volcanoes are. Most earthquakes directly beneath a volcano are caused by the movement of magma, which exerts pressure on the rocks until they crack. Then the magma squirts into the crack and starts building pressure again. Every time the rock cracks it makes a small earthquake. These earthquakes are usually too weak to be felt but can be detected and recorded by sensitive instruments. Once the plumbing system of the volcano is open and magma is flowing through it, constant earthquake waves, called harmonic tremor, are recorded, though not felt.
Four major types of seismograms: Top down: Deep quakes located away from the volcano; shallow volcanic quakes; surface events; harmonic tremor differences

However, most earthquakes are caused by the interaction of the plates not the movement of magma, but by plates sliding past each other, which causes friction and heat. Subducting plates melt into the mantle, and diverging plates create new crust material. Subducting plates, where one tectonic plate is being driven under another, are associated with volcanoes and earthquakes.
    It wasn’t until the 1960s that a full explanation began to develop regarding plate tectonics. This theory explained many pieces of the puzzle that scientists had observed, for example, continental fit, matching geology, etc. As a result, scientists now believe that the crust of the Earth consists of rigid interconnecting plates (six major plates and a few smaller ones). Plates are thought to float on the partially molten mantle, moving away from oceanic ridges where new plate material is produced and moving past each other or colliding along plate boundaries. Earthquakes and volcanoes are related to this movement.
    Plate material that is produced along the ocean floor is generally quite dense and relatively heavy. Continental plates don’t tend to get subducted, so when oceanic plate is pushed from the mid-ocean ridge towards a plate boundary with a continental plate, it tends to subduct or dive below the continental crust. In this process, water is also being subducted with the oceanic plate. Friction increases the heat along such boundaries, which causes this material to melt and mix the oceanic plate material, the continental plate material and the water.
    Where plates come into contact, energy is released. Subducting plates are associated with volcanoes and earthquakes. Andesite volcanoes tend to form at these subduction boundaries, which may have something to do with differences in plate densities and the release of gases, such as water vapor. As more heat is being produced through the subduction process, the mix of more and less volatile ingredients causes changes in density and pressure, which are linked to volcanic activity.
The outer shell of the earth, the lithosphere, is broken up into tectonic plates is broken up into 12 plates. While the seven major plates are shown above, there are also the Juan de Fuca, Cocos, Caribbean, Nazca, Scotia, Arabian, and Philippines plates

Thus, the activity focused along the edge of the plate boundary where two plates come into contact, such as the Chilean-Pampean flat slab that links to the subduction of the Nazca plate beneath the South America plate, form regions such as the Pacific Ring of Fire—a chain of earthquake and volcanic activity around the edge of the Pacific Ocean that generates 75% of the world’s volcanoes and 80% of the world’s earthquakes.
    The linkage between earthquakes and volcanoes are often found in the same place, as one likely triggers the other, though van be independent events. When a volcano erupts, the pressure of the rising magma forcing its way through the crust to the surface will often trigger earthquake activity. Scientists have been able to demonstrate this link and also know what type of earthquake observe.
    Conversely, an earthquake may trigger subsequent eruptions. As the crust changes and moves in a major earthquake, fissures or cracks can form that may act as pipelines for magma and future volcanoes. This is harder to monitor and test and is an area of active research.
    The point of this is to show that earthquakes are very well known and understood once they happen—prediction is an entirely different thing. But for understanding after the fact, the magnitude of an earthquake, that is, the measurement of its shaking strength, is easily recorded.
    Now, this leads us to one factor not considered by many theorists who claim that the wordage “As never had been known in all the land” (3 Nephi 8:5.7), meaning that no such event had ever before been seen in the Land of Promise.”
    However, for an event to be called “never had been seen before” does not necessarily exclude such events previously occurring, just that one of such magnitude or destruction had never before been seen.
The Greatest Earthquake to have occurred in recorded history

As an example, the earthquake that hit Lumaca in Chile in the spring of 1960, is referred to as the greatest and most powerful quake that had ever been recorded. It was called “Gran Terremoto de Chile” meaning “The Great Earthquake in Chile.”
    Consider that the Chilean quake of 1960, as stated earlier, was 150 times stronger than the next strongest earthquake recorded in Chile, and 300 times greater than the typical quake in that land. Thus, lit could be said about the 1960 quake that anything like it “had never before been seen in the land.”
    The point is Chile has known many great earthquakes. In fact, as stated earlier, five of the ten worst earthquakes in recorded history took place in Chile. But this one in 1960 is considered the one unlike any other that had ever occurred.
    It seems obvious that Mormon’s statement in 3 Nephi 8, that no other quake, storm, and event as happened following the Savior’s crucifixion had ever been seen in the land before that.
    This should suggest to even the most skeptical that the Land of Promise had a history of earthquakes, storms, and weather events; however, none had ever been so great as this one.
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3 comments:

  1. The most volcanic activity in our solar system is on Jupiter's moon IO. Scientists believe it is caused by land tidal friction heating. The Earth is known to have a land tide of about 12 inches. Where is the corresponding discussion that Earth's land tidal friction may contribute to earthquakes and volcanic activity?

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    1. The gravity of earth does not cause any volcanic activity on our moon like the huge Jupiter does to Io. Our moon is large compared to moons around the other planets. Even though our moon effects our tides, I would think that it would not be strong enough to cause any of our volcanic activity. But maybe I am wrong.

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  2. We also have a modern history with a global news network that has witnessed many earthquake and weather events. Yet we have never seen anything like what Mormon described. Most are complacent to think that our modern observation indicates a kind of endless calm, only disturbed occasionally by newsworthy outbursts of mother nature. That will change.

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