Articles and Aftershocks

Today, we're going to be learning about aftershocks. Aftershocks happen after the subsequent earthquake, and can actually cause more damage. Imagine if you're in a building rght after an earthquake. Everyone is doing damage check, finding out who's okay, who isn't, a whole host of things. It's been maybe 20-30 minutes, but everyone is still pretty shaken up. And then, BOOM! The ground starts shaking again, and chaos breaks out once again. Already weakened buildings are hit with another wave of shaking that they may not be able to take.

Picture courtesy of cbc.ca


But aftershocks don't just happen right after the earthquake. They can continue to happen days, weeks, months, even YEARS after the initial quake. Earthquakes in the middle of the continent can actually be aftershocks! Some big earthquakes happened in America in the 1800s and most mid-continental earthquakes are thought to be just aftershocks. A study is being done on this, and it could actually help predict future earthquakes, especially ones not near any fault lines.
Larger earthquakes can also trigger aftershocks far away. This is interesting because aftershocks used to be thought of as ones that happened after an earthquake near where the epicenter was. But it was discovered that large
earthquakes could trigger aftershocks far away, and this has further increased
our knowledge of a lot of things earthquake-wise.

Picture courtesy of earthquakes.usgs.gov

Citation:
Information


United States Geological Survey. "Rare great earthquake in April triggers large aftershocks all over the
globe." ScienceDaily, 26 Sep. 2012. Web. 06 Dec. 2012.

 "Earthquakes Can Trigger More Earthquakes, Experts Say." National Geographic. National Geographic Society,
n.d. Web. 06 Dec. 2012.

 "Not Exactly Rocket Science." Not Exactly Rocket Science. Discover Magazine, n.d. Web. 06 Dec. 2012.

Photographs:

N.d. Photograph. Earthquakes.usgs.gov. US Geological Survey, 24 July 2012. Web. 06 Dec. 2012. <http://

earthquake.usgs.gov/learn/glossary/?term=aftershocks>.

 "Not Exactly Rocket Science." Not Exactly Rocket Science. Discover Magazine, n.d. Web. 07 Dec. 2012.

Introductory Post

The ground is shaking. Choruses of, "Is this an earthquake?" "What the heck!" "Why is this happening!" ring out all around. Things are crashing to the ground, and you can hear chaos everywhere. All the kids in class scramble under their desks, confusion still everywhere. At last, the shaking stops.  Everyone seems in a panic, and debris is strewn everywhere. As you look around, a single thought echoes in your mind.
"How in the world did that just happen?"

Earthquakes aren't all that rare. According to the US Geological Survey website, there are an estimated 1,000,000+ earthquakes per year. Most of these are less than magnitude 2.9, meaning they really cannot be felt.
To understand the reason behind earthquakes, you have to have a few facts first. Way under the surface of the earth, there are things called tectonic plates. They basically float on the magma very slowly, and don't move very much per year, about 2 centimeters. But many times, these plates suddenly slip against each other because of built up friction, causing earthquakes. The place under the ground where this happens is the hypocenter, and above the ground it is the epicenter. The place where the rock slips is called the fault plane.
So earthquakes are basically tectonic plates rubbing against each other.
After the initial earthquake, something called the aftershock happens. Aftershock is less than the actual earthquake, but if the initial quake was big enough the aftershock can cause almost as much damage, sometimes more.




What do tsunamis have to do with earthquakes?
Many times, tsunamis happen because there was an earthquake way down on the sea floor. This slip acts like a paddle, and the energy transfers to the water. The water ends up going on until it eventually loses its energy, or until it hits land, whichever comes first.
Tsunamis can also be caused by underwater volcanoes, underwater explosions, and occasionally even landslides.


This is the base of learning things about tsunamis and earthquakes. As we dive further in, you will understand the science behind earthquakes and tsunamis better, as well as how they are measured. There are a lot of discoveries in store, so sit tight and hold on.
It's gonna be a quakey ride.