Continued from the previous post regarding the unusual and specific wordage of events that accompanied the destruction outlined in 3 Nephi and Helaman 14, and the earthquakes and volcanoes behind the destruction. The first ten were covered in the previous posts. Here we pick up with the continuation of item #11:
(11. Continued)
Another of the common observation is land instability, that is the cracking and movement of the ground down slope or towards unsupported margins of rivers, streams, or the coast. The failure of ground in this manner is called “lateral spreading,” and may occur on very shallow slopes with angles only 1 or 2 degrees from the horizontal.
Heavy amounts of water seeping into the ground can liquefy the soil as a result of earthquake agitation and make it ground unstable, especially for large structures
What is often referred to as “quicksand,” which is a colloid consisting of fine granular material (fine sand, very fine micron-sized particles of clay), and water, with densely packed sand at the bottom, and water floating on top of it. The “quicksand” forms when water saturates (such as from a heavy prolonged rain storm) an area of loose sand, which is agitated. When the water trapped in the batch of sand cannot escape, it creates liquefied soil that can no longer resist force and cannot support weight. Quicksand can be formed by standing or (upwards) flowing underground water agitated by high magnitude earthquakes. In fact, at higher stresses (high magnitude and/or prolonged earthquake), quicksand liquefies very quickly, and the higher the stress the more fluid it becomes and the further dense objects, such as buildings sink.
In the case of flowing underground water, the force of the water flow opposes the force of gravity, causing the granules of sand to be more buoyant. In the case of earthquakes, the shaking force can increase the pressure of shallow groundwater, liquefying sand and silt deposits. In both cases, the liquefied surface loses strength, causing buildings or other objects on that surface to sink.
The saturated sediment may appear quite solid until a change in pressure or a shock initiates the liquefaction, causing the sand to form a suspension with each grain surrounded by a thin film of water. This cushioning gives quicksand, and other liquefied sediments, a spongy, fluid-like texture. Objects in the liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced sand and the object floats or sinks due to its buoyancy.
A house on the way to sinking out of sight in liquefied ground following an earthquake
When the six cities in the Land of Promise sunk into the ground, the Disciple Nephi observed: “the city of Gadiandi, and the city of Gadiomnah, and the city of Jacob, and the city of Gimgimno, all these have I caused to be sunk, and made hills and valleys in the places thereof; and the inhabitants thereof have I buried up in the depths of the earth” (3 Nephi 9:8). Another city was buried in the earth “ and also “the city of Gilgal have I caused to be sunk, and the inhabitants thereof to be buried up in the depths of the earth” (3 Nephi 9:6).
While only a few of the cities in the Land of Promise are mentioned in Chapter 8 and 9 of 3 Nephi, there were many, many more cities in the land. In fact, Nephi reports seeing so many cities in the Land of Promise, he could not count them. As he described his vision: “And it came to pass that I beheld many generations pass away, after the manner of wars and contentions in the land; and I beheld many cities, yea, even that I did not count them” (1 Nephi 12:3, emphasis added).
Of the cities described as being destroyed, some sank into the ground, with the earth filling in above them, effectively burying all the people and the entire city beneath the surface. It would seem from this that the ground around and beneath the cities and buildings were on soil, that once it liquefied, the buildings were too heavy to be supported and down the city fell never to be seen again.
12. 3 cities sunk into the sea (3 Nephi 8:9).
Earthquakes are a key factor which trigger most major submarine landslides. In fact, earthquakes provide significant environmental stresses and can promote elevated weak water pressure which leads to failure that cause submarine landslides, which are turbidity currents that consist of water-saturated sediments flowing downslope.
Earthquake-caused submarine slides run down slope and travel ending up as much as hundreds of miles away
In the most typical case of oceanic turbidity currents, sediment laden waters situated over sloping ground will flow down-hill because they have a higher density than the adjacent waters. The driving force behind these currents is gravity acting on the high density of the sediments temporarily suspended within a fluid. These semi-suspended solids make the average density of the sediment bearing water greater than that of the surrounding, undisturbed water.
As such currents flow, they often have a “snow-balling-effect,” as they stir up the ground over which they flow, and gather even more sedimentary particles in their current. Their passage leaves the ground over which they flow scoured and eroded as reaching the calmer waters of the flatter area of the oceanic abyssal plain (main oceanic floor), the particles borne by the current settle out of the water column. The sedimentary deposit of a turbidity current is called a turbidite.
A turbidity Current is a rapid, downhill flow of water caused by increased density due to high amounts of sediment, and can be caused by earthquakes and other geological disturbances
Such turbidites slide all the way into the deep ocean troughs below the continental shelf (can also occur in deep lakes) by underwater avalanches which slide down the steep slopes of the continental shelf edge. When the material comes to rest in the ocean trough, it is the sand and other coarse material which settles first followed by mud and eventually the very fine particulate matter. It is this sequence of deposition that creates the Bouma sequence, which is deposited during the waning flow as turbidity currents, and all that they carry, move downslope as the flows steadily lose energy as they react to changes in the slope of the surface over which they travel.
An example of this occurred during the 1929 Grand Banks 7.2 earthquake (12 miles deep) that struck the continental slope off the coast of Newfoundland. Minutes later transatlantic telephone cables began breaking sequentially, farther and farther downslope, away from the earthquake’s epicenter. Twelve cables were snapped in a total of 28 places. Exact times and locations were recorded for each break, providing investigators with information that a 60-mile-per-hour submarine landslide or turbidity current of water-saturated sediments swept 400 miles down the continental slope, snapping the cables as it passed (B.C. Heezen and W. M. Ewing, “Turbidity currents and submarine slumps, and the 1929 Grand Banks earthquake,” American Journal of Science, vol.250, no.12, Elsevier Publishing, Amsterdam, Netherlands, 1952, pp849–873).
An electrical storm at sea. Surrounded by water in the Land of Promise, such an event like this would have been likely
In addition, over the sea, a storm can whip up huge waves, that when they reach land, can flood large areas, including towns and cities. If the water doesn’t subside, the ground can liquefy, especially if a tsunami is caused—and can cover the towns or cities permanently as it creates lakes and swamps.
When the disciple Nephi observed cities disappearing into the ground and being covered over, he well might have seen the liquefying result of the three-hour earthquake in the Land of Promise either inland or along the shore. The former cause by the earth giving way into the aquafer, the latter along the shore and into the sea.
(See the next post, “Were there Really Earthquakes? – Part VII, for more on the unusual and specific wordage of events that accompanied the destruction, and the understanding that earthquakes and volcanoes resulting in the destruction outlined in 3 Nephi, and continuing with the list of events, the first twelve in previous posts and continuing here with #13):
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