Earthquake
January 12, 2010 4:53 PM, 15 miles WSW of Port-Au-Prince, Haiti, the ground began to shake with a 7.0 magnitude earthquake. 8 miles below the earth surface the Enriquillo-Plantain Garden fault was slipping with the Caribbean plate moving eastward against the North American plate.
Unconfirmed historical earthquakes associated with this fault occurred in 1860, 1770, 1761, 1751, 1684, 1673 and 1618. A 5.9 magnitude after shock occurred at 5:00 PM followed by another 5.5 magnitude at 5:12 PM and then a 5.7 magnitude 2 minutes after midnight. Eight days later on January 20th at 6:03 AM a 6.1 magnitude struck again 35 miles WSW of Port-Au-Prince.
The problem with earthquakes is the time span between them. Generations may go by before a major one hits again. People become lax, building codes relaxed and disaster strikes.
The Richter scale, which records the magnitude of a quake doubles for every 0.2 increase. For example a 7.0 quake would be 32 times stronger than a 6.0 quake. The earth’s crust is a mere 6.5 miles thick in mid ocean and an average of only 25 miles thick under the land masses. Think of the earth’s crust compared to the skin of an apple, then imagine the apple drying out and wrinkling. Well that is not quite how it happens but it looks that way.
The crust is made up of large plates that are constantly on the move. The problem is that they are moving in different directions. When the plates grind against each other we have a fault and earthquakes. In other places one plate may be forced under another plate called subduction zones.
The subduction zone where the Chile Ridge oceanic plate is slipping under the South American plate created the largest recorded earthquake. On May 22, 1960 a 9.5 magnitude quake occurred off the coast of Chile. The sudden change in the ocean floor created huge tsunami in the Pacific.
Subduction zones are found in the deep valleys of the oceans and result in most of the deaths due to the resulting tsunamis.
What drives these plates? It would have to be the strongest force on earth, the Mid-Atlantic Ridge. The Mid-Atlantic Ridge is a mountain range that extends half way around the world. Running north and south through the Atlantic ocean. The ridge is growing through volcanos along the center of its length, pushing the North American plate west and the Eurasian plate east.
The question is whither the ridge is the result of the two plates moving apart or is it causing the plates to move.
The Core of the earth is like a boiling pot, with heat rising toward the surface and cooler areas falling toward the center. Convection and the release of heat from the Earth’s core drives further convection in the mantle. The portion of the mantle that is closest to the crust is plastic and flows easily. Convection in the mantle drives plate tectonic motions of the sea floor and continents. This convection is not even, just as currents in the ocean are not all the going in the same direction. These rivers of lava push against the bottom of mountains and move continents or continental plates. An excellent paper on the Earth’s Interior & Plate Tectonics can be found at http://www.solarviews.com/eng/earthint.htm.
The Pacific Ring of Fire is the most active earthquake and volcano area in the world. The Pacific rise is expanding and the continents of the Americas and Asia are pushing toward each other to create the Ring of Fire around the Pacific with subduction zones on both sides of the ocean.
Mountain uplift and folding
With all the pressure being applied to the edges of some of the continents, mountains are being pushed up and some that have eroded down are floating back up to stabilize on the ocean of mantle below. This results in the many smaller earthquakes in the eastern US and other parts of the world. This mountain uplifting has created faults along mountain sides and of course this results in caves being formed in the crevasse formed by this activity. As caving is my hobby, I have a special interest in all this activity. Cavers have reported not even noticing an earthquake during a cave trip, even when the quake was near by. All the rock moves together and being inside you have no reference to gauge the movement. Of course these are usually a magnitude of 3 or less. We do see plenty of fault evidence in the caves and they sometimes give clues to more cave passage to explore. There have also been freak accidents where large boulders have fallen on cavers that may have been caused by small quakes.
The Lake County uplift, about 31 miles long and 14 miles wide, up warps the Mississippi river valley as much a 32 feet in parts of southwest Kentucky, southeast Missouri, and Northwest Tennessee. The Tiptonville dome is the largest and highest topographic relief on the Lake County uplift. It is 8.7 miles wide and 6.8 miles long. Uplifting of this dome occurred during the earthquakes of 1811-1812. The ground subsided to the east of the Tiptonville dome during the same time and formed Reelfoot Lake. Some areas subsided as much as 16 feet. This area is also know as the New Madrid Seismic Zone, New Madrid Fault Line or Reelfoot Rift.
The most well documented and accurate prediction of an earthquake was the earthquake of December 16, 1811. The first quake was an estimated magnitude 8.1 followed by four other quakes of magnitude 8.0 or higher through February 7, 1812. The area of strong shaking associated with these shocks is two to three times larger than that of the 1964 Alaska Quake and 10 times larger than that of the 1906 San Francisco earthquake.
Tecumseh was born March 9, 1768 under a shooting star called the Panther, his name means Panther-Across-The-Sky. Leading up to the War of 1812 Tecumseh was well know as a diplomat, a peacemaker and a prophet. He prophesied to the day the first of the long series of quakes months before. It was the signal for all the Indian tribes to go to war with the whites. An accurate account of the events can be found in the book The Frontiersmen a narrative by Allan W. Eckert.
In December, 1809, Tecumseh planned to visit each chief of all the tribes he was trying to bring together. But before he set out he gave strict instructions to his younger brother to go into the woods and make a large number of sacred slabs. Each slab was to be the same length, thickness and taper, and each was to have carved, on one side only, the same symbols. They were to be made of red cedar and each was to be supplied with a bundle of thin red sticks. Each stick was to represent one moon, and, when the bundle and slab was given to a particular chief, he would be directed to throw away one of the red sticks at each full moon until only the slab remained, at which time he must prepare for the great sign to be given. The meaning of the symbols, known only to the Indians on both sides of the Mississippi River were to come directly to Detroit to take over the fort. As he traveled through the southern tribes and handed out the slabs and bundles of sticks, the bundles were becoming smaller, so that the timing would be that all would run out of sticks at the same time.
Big Warrior, chief of the Upper Creeks, in the village of Tuckabatchee located on the Tallapoosa River, was hard to convince. Tecumseh told him that as a sign, that he would leave Tuckabatchee and go directly to Detroit. When I arrive there, I will stamp on the ground with my foot, and shake down every house in Tuckagatchee! Big Warrior agreed to follow if and when this took place.
When all of the tribes were down to the last red stick, they were told that they would be given a preliminary sign in six days. A great star would flash across the sky. They were then to divide the last stick into thirty equal pieces. Each day thereafter, one of thede pieces was to be burned in the light of dawn, but the thirtieth and last piece was to be burned in the midst of the night. Then the would come the great sign which he had told them about. They would then all converge on the British fort Malden on Lake Erie.
Saturday, November 16, 1811
Under a crisp cloudless sky, the Indians crouched. No fires were lit as to not interfere with the sign. There was also no moon and the stars were bright. From southern Canada, western New York and Pennsylvania, they watched. In Ohio and the Indiana Territory to the land between the lakes and the land west of the lakes they watched. Along the Mississippi and Missouri, and even farther west, they watched. In the Tennessee and Alabama and Mississippi country, they watched. And each chief held in his hand the final red stick.
Just before midnight it came — a great searing flash from out of the southwest; incredibly bright with a weird greenish-white light, swift and awe-inspiring as the heads of a hundred thousand Indians swivelled to watch its progress across the heavens until it disappeared in the northeast.
Many of the chiefs broke their sticks over their knees and threw them away in fear and anger. But there were some who carefully measured, marked it off with a bit of charcoal, and cut it into thirty equal lengths. And then they waited.
Monday, December 16, 1811
At 2:30 AM the earth shook.
In the south of Canada, in the villages of the Iroquois, Ottawa, Chippewa and Huron, it came as a deep and terrifying rumble. Creek banks caved in and huge trees toppled in a continuous crash of snapping branches.
In all of the Great Lakes, but especially Lake Michigan and Lake Erie, the waters danced and great waves broke erratically on the shores, though there was no wind.
In the western plains, there was a fierce grinding sound and a shuddering, which jarred the bones and set teeth on edge. Earthen vessels split apart and great herds of bison staggered to their feet and stampeded in abject panic.
To the south and west, tremendous boulders broke loose on hills and cut swaths through the trees and brush to the bottoms. Rapidly running streams stopped and eddied, and some of them abruptly went dry and the fish that had lived in them flopped away their lives on the muddy or rocky beds.
To the south, whole forests fell in incredible tangles. New streams sprang up where none had been before. In the Upper Creek village of Tuckabatchee, every dwelling shuddered and shook, and then collapsed upon itself and its inhabitants.
To the south and east, palm trees lashed about like whips, and lakes emptied of their waters, while ponds appeared in huge declivities which suddenly dented the surface of the earth.
All over the land, birds were roused from their roosting places with scream of fright and flapping wings. Cattle bellowed and kicked, lost their footing, and were thrown to the ground where they rolled about, unable to regain their balance.
In Kentucky, Tennessee and the Indiana Territory, settlers were thrown from their beds, heard the timbers of their cabins wrench apart, and watched the bricks crumble into heaps of debris masked in choking clouds of dust. Bridges snapped and tumbled into rivers and creeks. Glass shattered, fences and barns collapsed and fires broke out. Along steep ravines, the cliffside slipped and filled their chasms, and the country was blanketing with a deafening roar.
In the center of all this, in that area where the Ohio River meets the Mississippi, where Tennessee, Kentucky, Arkansas, Missouri, and Illinois come together, fantastic splits appeared in the ground and huge tracts of land were swallowed up. A few miles from the Mississippi, near the Kentucky-Tennessee border, a monstrous section of ground sank as if some gigantic foot had stepped on the soft earth and mashed it down. Water gushed forth in fantastic volume and the depression became filled and turned into a large lake, to become known as Reelfoot Lake. The whole mid-section of the Mississippi writhed and heaved and tremendous bluffs toppled into the muddy waters. Entire sections of land were inundated, and others that had been riverbed were left high in the air. The Mississippi itself turned and flowed backwards for a time. It swirled and eddied, hissed and gurgled, and at length, when it settled down, the face of the land had changed. New Madrid was destroyed and the tens of thousands of acres of land, including virtually all that was owned by Simon Kenton, vanished forever; that which remained was ugly and austere.
Such was the great sign of Tecumseh.
This was the earthquake which occurred where no tremor had ever been recorded before; where there was no scientific explanation for such a thing happening; where no one cold possibly have anticipated or predicted that an earthquake could happen. No one except Tecumseh.
And though they were only a small percentage of those who had pledged themselves to do so, nevertheless quite a number of warriors of various tribes gathered up their weapons and set out at once to join the amazing Shawnee chief near Detroit.
From the book The Frontiersmen by Allan W. Echert.
The second quake occurred at 8:15 AM on December 16, 1811 with about the same magnitude.
The third quake occurred at Noon on December 16, 1811 also about the same magnitude.
The forth quake occurred at 9:00 AM on January 23, 1812 with a magnitude of 7.8.
And the fifth quake occurred at 3:45 AM on February 7, 1812 this last quake had several destructive shocks on February 7, the last of which equaled or surpassed the magnitude of any previous event. The town of New Madrid was destroyed. At St. Louis, many houses were damaged severely and the chimneys were thrown down.
For almost two years strong aftershocks were felt in the area and currently smaller quakes are still occurring. Five towns disappeared, in Missouri Little Prairie and Lost Village, in Arkansas Big Prairie (Rebuilt as Helena) and New Madrid. Fort Jefferson, Ky was also disappeared though only a few people were living there at the time. New Madrid had the largest population and was rebuilt further north on the new Mississippi bank with a population of 1,548. To give you an ideal of the population density the population of St. Louis after the quake was only 3,149, Cape Girardeau 2,026, Ste. Genevieve 1,701 and St. Charles 1,096.
The quakes were felt in 28 states and the District of Columbia.
People and Earthquakes
New York City, New York
August 10 at 19:07 UTC
Magnitude 5.5
This severe earthquake affected an area roughly extending along the Atlantic Coast from southern Maine to central Virginia and westward to Cleveland, Ohio. Chimneys were knocked down and walls were cracked in several States, including Connecticut, New Jersey, New York, and Pennsylvania. Many towns from Hartford, Connecticut, to West Chester, Pennsylvania.
Property damage was severe at Amityville and Jamaica, New York, where several chimneys were “overturned” and large cracks formed in walls. Two chimneys were thrown down and bricks were shaken from other chimneys at Stratford (Fairfield County), Conn.; water in the Housatonic River was agitated violently. At Bloomfield, N.J., and Chester, Pa., several chimneys were downed and crockery was broken. Chimneys also were damaged at Mount Vernon, N.Y., and Allentown, Easton, and Philadelphia, Pa. Three shocks occurred, the second of which was most violent. This earthquake also was reported felt in Vermont, Virginia, and Washington, D.C. Several slight aftershocks were reported on August 11.
Source: Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527
People seem to collect in earthquake prone areas. Maybe it is because of the bays and waterways.
formed by the faults. A rift in the crust runs along underneath the 125th street in New York and is known as the 125th Street Fault. The fault line creates a fault valley deep enough to require the IRT Broadway-Seventh Avenue Line to become a trestle bridge between 122nd and 135th Streets. The street in the 18th century was called The Hollow Way.
Compare the population density of the US with damaging quakes and you can clearly see that we live in all the wrong places.
As recent as 2009 a mild earthquake has occurred in the New York City area.
Morristown, New Jersey 34 miles from New York City
February 03, 2009 at 03:34:19 UTC
Magnitude 3.0
A year later, 40 miles from Chicago, IL.
February 10, 2010 at 14:00:04 UTC
Magnitude 3.8
In poorer areas where building codes are not up to earthquake standards the death toll is much higher even with moderate earthquakes.
Deadest Quakes in the World:
Date
Location Deaths Magnitude Jan. 23, 1556 Shansi, China 830,000 ~8 July 27, 1976 Tangshan, China 255,000 [1] 7.5 January 12, 2010 Port-Au-Prince, Haiti 230,000 7.0 Aug. 9, 1138 Aleppo, Syria 230,000 n.a. Dec. 26, 2004 off west coast of northern Sumatra 225,000 + 9.0 Dec. 22, 8562 Damghan, Iran 200,000 n.a. May 22, 1927 near Xining, Tsinghai, China 200,000 7.9 Dec. 16, 1920 Gansu, China 200,000 7.8 March 23, 8932 Ardabil, Iran 150,000 n.a. Sept. 1, 1923 Kwanto, Japan 143,000 7.9 Oct. 5, 1948 Ashgabat, Turkmenistan, USSR 110,000 7.3 Dec. 28, 1908 Messina, Italy 100,000 [2] 7.2 Sept. 1290 Chihli, China 100,000 n.a. May 12, 2008 Eastern Sichuan, China 87,587 7.9 Oct. 8, 2005 Pakistan 80,361 7.6 Nov. 1667 Shemakha, Caucasia 80,000 n.a. Nov. 18, 1727 Tabriz, Iran 77,000 n.a. Dec. 25, 1932 Gansu, China 70,000 7.6 Nov. 1, 1755 Lisbon, Portugal 70,000 8.7 May 31, 1970 Peru 66,000 7.9 May 30, 1935 Quetta, Pakistan 60,000 7.5 Jan. 11, 1693 Sicily, Italy 60,000 [2] n.a. 1268 [3] Silicia, Asia Minor 60,000 n.a. June 20, 1990 Iran 50,000 7.7 Feb. 4, 1783 Calabria, Italy 50,000 n.a.
Largest earthquakes by magnitude:
Date Location Magnitude May 22, 1960 Valdivia, Chile 9.5 December 26, 2004 Off west coast of northern Sumatra, Indonesia 9.3 March 27, 1964 Prince William Sound, Alaska, USA 9.2 November 4, 1952 Kamchatka, USSR 9.0 January 26, 1700 Cascadia subduction zone 9 [2] January 31, 1906 Colombia-Ecuador 8.8 February 4, 1965 Rat Islands, Alaska, USA 8.7 November 25, 1833 Sumatra, Indonesia 8.8-9.2 [2] November 1, 1755 Lisbon, Kingdom of Portugal 8.7 [2] March 28, 2005 Sumatra, Indonesia 8.6-8.7 [2] March 9, 1957 Andreanof Islands, Alaska, USA 8.6 December 16, 1920 Ningxia-Gansu, China 8.6 August 15, 1950 Assam, India – Tibet, China 8.6 December 16, 1575 Valdivia, Kingdom of Chile 8.5 September 12, 2007 Sumatra, Indonesia 8.5 October 16, 1737 Kamchatka, Russian Empire 8.3 [2]
1. Official. Estimated death toll as high as 655,000.
2. Estimated.
3. No date available.
Source: National Earthquake Information Center, U.S. Geological Survey.
Largest earthquake in North America
Anchorage Alaska earthquake
March 27, 1964, at 5:36 PM local time in Alaska, a Magnitude 9.2 earthquake occurred in Prince William Sound. This was also the third largest recorded in the world.
This subduction zone was created by the Pacific plate sliding under the North American plate 16 miles underground between Valdez and Anchorage. The vertical thrust of the fault generated a tsunami that reached Hawaii and ran down the Pacific Coast of North America. Ground waves of over 3 feet high were reported as the ground turned to liquid and became unstable. In Anchorage, Post tension cables in concrete buildings became missiles as they shot out of the buildings and flew for blocks. Part of main street sunk into a 10 foot hole and major damage occurred to buildings in a 30 block radius. The air traffic control tower collapsed and water, sewer, gas lines ruptured. Remarkable only nine deaths were reported.
Twenty eight people were killed in Valdez where the wave entered the harbor and lifted a freighter thirty feet destroying the dock. Twelve people died in Seward were fires broke out at a large oil storage facility.
Two canneries were wiped out in Kodiak and Eight people died. The tsunami traveling at an estimated 400 miles per hour washing away 55 homes and damaged 375 others in Port Alberni, British Columbia, Canada. Twelve more were killed in Crescent City, California and four dide in Beverly Beach State Park in Oregon.
Deaths in Alaska were low due the Good Friday Holiday, and a low population density.
Most well known earthquake in North America
The 1906 San Francisco Earthquake
The San Andreas Fault neat San Francisco is the most well known and most studied Fault zone in the world. The 7.7 to 8.3 magnitude quake centered near Daly City, a suburb of San Francisco occurred on April 18th, 1906 and 5:12 AM. There were over thirty major fires and an estimated 3,000 deaths with 250,000 left homeless. 25,000 buildings in 490 city blocks were destroyed. Fires burned for 4 days. The bay area were the land was filled in on the bay suffered the most damage. The Fault ruptured the ground for 296 miles along the northern section of the San Andreas Fault with a displacement of twenty feet on each side of the fault in places.
On October 17, 1989 at 5:04 PM local time, a 7.1 magnitude earthquake occurred ten miles north of Santa Cruz and became known as the Loma Prieta or World Series Quake. This was on a parallel fault to the San Andreas Fault and occurred at the start of the third game of the World Series. Millions of people were watching and lost video at the time of the quake.
Several years before the quake my family and I were traveling the Viaduct on the Nimitz Freeway while vacation in the Bay area, and I can remembering commenting about what would happen if there were an earthquake and the upper level came down. I was happy to get off that road. Forty two people were crushed in their cars on that Viaduct when the upper deck collapsed.
A fifty foot section of the San Francisco-Oakland Bay Bridge upper level also fell to the lower deck. Six people were killed in Santa Cruz were forty buildings collapsed.
Comets and Earthquakes
The Great Comet of 1811, formally designated C/1811 F1, is a comet that was visible to the naked eye for around 260 days, a record it held until the appearance of Comet Hale-Bopp in 1997. In October 1811, at its brightest, it displayed an apparent magnitude of 0 (equal to the brightness of the star Vega magnitude 0, the brightest star Sirius has a magnitude -1.47), with an easily visible coma.
From May-August, the comet’s position made it difficult to spot because of its low altitude and the evening twilight. By September, in Ursa Major, it was becoming a conspicuous object in the evening sky as it approached perihelion: William Herschel noted that a tail 25° long had developed by October 6.
By January 1812, the comet’s brightness had faded. Several astronomers continued to obtain telescopic observations for some months.
The Great Comet of 1811 was thought to have had an exceptionally large coma, perhaps reaching over 1 million miles across – fifty percent larger than the Sun. The comet’s nucleus was later estimated at 30-40 km in diameter and the orbital period was calculated at 3,065 years. In many ways the comet was quite similar to Comet Hale-Bopp: it became spectacular without passing particularly close to either the Earth or the Sun, but had an extremely large and active nucleus.
From Wikipedia, the free encyclopedia.
The comet was nearest Earth (1.22 AU) on October 16. (AU is equal to the mean distance between the earth and sun.)
It is very interesting that the earthquakes of 1811-1812 were noted by the North American Indians, as being predicted by the sign of the 1811 comet.
Conclusion
Earthquakes are a constant reminder of just how young and fragile our present home here on this earth is. When the Bible recommends building your house on a rock, it has a double meaning. Not only a stable foundation for our homes, but Christ the Rock as a stable foundation for our lives. Just as the moon pulls on the oceans of the world and creates the tides, the moon also pulls on the molten rock just under our feet to cause pressure on the earth’s crust. These external forces may not be the cause of earthquakes, but they could be the straw breaks the camels back.
If we can learn to measure the stresses in the earth’s crust and then watch for the things that trigger quakes, then someday we may be able predict earthquakes.
Hubert Crowell Retired and working part time. Hobbies are caving and propecting for gold. Please visit my web page at: http://www.hucosystems.com/
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