The Explainer General
Gigantic earthquakes rocked the Midwestern United States between December 16, 1811, and February 7, 1812. A fault in our continent’s stone base runs beneath the Mississippi River near what is now New Madrid, Missouri. Unequal pressures built up on both sides of this fault and the sides slipped to ease the pressure. Whammo—the first of 3 earthquakes from these slips was felt as far away as New York City, Washington, DC, and Charleston, South Carolina.
There were no scientific instruments to measure the New Madrid Quakes in 1812 so geologists have sifted through widespread accounts from old journals and newspapers for data. Putting the accounts together on a map, we know the quakes were felt over an area of 1,930,000 square miles. They earthquakes began with a pair of terrific shocks at 2:15 and 7:15 local time on the morning of December 16, 1811, both measuring 7.2 - 8.1 on the Richter scale. They were followed by a 7.0 - 7.8 quake on January 23, 1812, and a 7.4 - 8.0 event on February 7, 1912.
The quakes were violent, earth-shifting events. There have been even more powerful earthquakes in Alaska and Hawaii, both vulnerable to deep geological pressures, but the New Madrid quakes are the largest to ever occur in the original forty-eight states. Yet little damage or loss of life was reported. The region was then part of Louisiana Territory, sparsely inhabited with small villages and only a few multi-story masonry buildings. We can’t know how many log cabins or small home chimneys were thrown down, or how many Native Americans were affected.
Coincidentally, the first steam paddle-wheeler on the Mississippi, the New Orleans, invented by Robert Fulton, was making its first trip south during the quakes. Land heaves caused massive waves to travel up and down the river. When the little southbound New Orleans met one of these waves it seemed that the great Mississippi was running backward. Some land rose, riverbanks crumbled, some land subsided and formed new lakes. The river’s course was so changed that maps were useless, and the steamboat did a remarkable job of “feeling its way” through the new channels to dock at New Orleans on January 10, 1812.
We’ve come to expect earthquake and volcanic activity around the Pacific “Ring of Fire,” and other hot-spots of geologic shift, but the New Madrid Quake was the product of an unexpected fault in earth’s crust we now call the New Madrid Seismic Zone. And, yes, there is the possibility of similar earthquakes from this zone in the future. The Earth that seems so solid is secretly restless.
Jan Adkins is not only a writer, but also a wonderful illustrator. His personal website is under construction at the moment, but if you would like to find out more about him and see a list of his very well known books, click here.
Adkins is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.
MLA 8 Citation
Adkins, Jan. "Earthquakes on the Mississippi?" Nonfiction Minute, iNK Think Tank, 25 Sept. 2017, www.nonfictionminute.org/the-nonfiction-minute/earthquakes-on-the-mississippi.
Sneed B. Collard III
Several years ago, I rode the world’s fastest elevator to the top of one of the world’s tallest buildings—Taipei 101. Shaped like an elegant stalk of bamboo, Taipei 101 soars 1670 feet above the island nation of Taiwan. However, the engineers who designed the building faced two monumental challenges. The first is that dozens of earthquakes shake Taiwan each year. The second is that in an average year, Taiwan gets hammered by three or four hurricanes, or typhoons.
How, engineers wondered, could they keep people comfortable inside Taipei 101 when it swayed back and forth? More important, how could they keep the building from getting damaged or collapsing in a massive earthquake or 100 mile-per-hour winds?
One solution: a damper ball.
Damping devices are weighty objects that can reduce the motion of a bridge, building, or other structure. In the case of Taipei 101, engineers placed the damper ball near the top of the building—the part that sways the most. The ball is hung from thick cables inside the building and rests on giant springs or “dampers.”
One of Isaac Newton’s basic laws of physics is that an object at rest tends to stay at rest—and the damper ball proves it. Every time Taipei 101 starts swaying, the damper ball wants to stay where it is and “pulls back” on the building, reducing how far the building moves. When the building sways in the opposite direction, the process repeats itself—but in the reverse direction. Of course the building also pulls on the damper ball, but the ball’s movements are restricted by the dampers it presses against.
Does the system work? You bet. The damper ball inside of Taipei 101 reduces the building’s movement by 30 to 40 percent!
Of course not just any damping device could protect an enormous building like Taipei 101. Taipei’s damper ball weighs 1.5 million pounds—as much as two fully-loaded jumbo jets. It is composed of 41 circular steel plates that stand taller than a one-story house. In 2008, when a giant earthquake hit mainland China, the people of Taiwan could feel it hundreds of miles away. The damper ball did its job, resisting Taipei 101’s movement, keeping the building safe. During Typhoon Soudelor in 2015, the damper again worked like a charm, protecting the building against 100- to 145-mile-per-hour winds.
Besides protecting Taipei 101, the damper ball has become a major tourist attraction. Each year, thousands of visitors ride to the 89th floor. They take selfies next to the damper ball. They even take “Damper Baby” souvenirs home with them. If you’re ever lucky enough to visit Taiwan, check it out!
The damper ball is visible between the 89th and 91st floor of Taipei 101 and has become an attraction for tourists.
Sneed B. Collard III is author of more than eighty award-winning children’s books as well as a new book for educators, Teaching Nonfiction Revision: A Professional Writer Shares Strategies, Tips, and Lessons.
Sneed is a dynamic speaker and offers school and conference programs that combine science, nature, and literacy. To learn more about him and his talks, visit his website,.
To learn more about the damper ball and watch how it performed during Typhoon Soudelor, check out this article and video: http://www.thorntontomasetti.com/taipei-101s-tmd-explained/
MLA 8 Citation
Collard, Sneed B. "Damping Down Danger." Nonfiction Minute, iNK Think Tank, 10
01 2018, www.nonfictionminute.org/the-nonfiction-minute/