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1. If an earthquake's strength was 9.9 what would
happen?
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The largest earthquake was a 9.5 event along the
coast of Chile in 1960. The second largest was a 9.2
along the southern coast of Alaska in 1964. A 9.9
earthquake would be 4/10 of a unit larger than that
of Chile, so it would release 10 raised to the power
(1.5*4/10) = 4 times as much energy. The fault
length would also be about 4 times longer, or 4,000
km. Although we don't expect an earthquake of this
size, one of the places it might conceivably occur
would be along the Aleutian/Alaska subduction zone.
This would require the entire zone to rupture in one
earthquake, which we don't think has ever happened.
Such an earthquake would both cause strong shaking
for 5 minutes or more as well as generate a large
ocean wave (tsunami) that would travel at 800
km/hour across the entire Pacific Ocean. This wave
could would have low amplitude over the open ocean
but would grow in height as it reached shorelines
and could cause a lot of damage to near shore
facilities and homes.
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2.
If there was an earthquake in your house what should
you do?
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If you feel an earthquake, duck and cover. Here's a
page with a bit of information on this. Be sure not
to panic!
Here's what is recommended at the FEMA site for
what to do during an earthquake: If you are indoors
during an earthquake, keep calm and take cover under
a heavy table or desk. Stay away from glass, windows
or anything that could fall, like a bookcase.
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3.If
3 tectonic plates met in the same place what would
happen?
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Often 3 tectonic plates do meet in one place. There
is a name for this: triple junction. Try a search
at for "triple junction" site:edu to see what you
can find out.
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4.
Why do so many of the earthquakes happen 33 Km down?
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When
the USGS National Earthquake Information Center
locates an earthquake we can always figure out what
the location (latitude and longitude) of the quake
are. However, often we can not determine the depth
of the earthquake. In those cases we assign the
depth to be 33 km. In reality few earthquakes occur
at 33 km depth, so some of these events are actually
shallower and some are deeper.
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5.
Is there a reason why so few earthquakes happened
between midnight and 04.00 UTC?
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Earthquakes happen all around the clock. If you can
show that fewer earthquakes occur between midnight
and 4 AM, then this would be worthy of a scientific
publication, as it is not common knowledge. Making
an observation like this is what science is all
about, but you will have to prove to other
scientists that what you say is true.
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6.
If you fell into a crack caused by an earthquake
where would you land?
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Cracks in the Earth caused by earthquakes are not
very deep. If you fell into one, chances are that
you could just stand up and climb out. Falling into
a crack is the absolutely least likely way that you
could be injured by an earthquake. For the most part
it's buildings and other man-made structures that
cause injury during an earthquake.
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7.
Are there more earthquakes under the sea than land?
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Areas of subduction, where an oceanic plate is
sinking down into the Earth, are the sources of much
of the World's earthquakes. Hence, more earthquakes
occur under the sea than under the land.
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8.
We were looking at earthquakes above 5.0 on the
Richter and found most were between 5.5 and 5.8, is
there a reason for this?
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The distribution of the sizes of earthquakes is such
that there are 10 times more 6's than 7's 10 times
more 5's than 6's 10 times more 4's than 3's 10
times more 3's than 4's 10 times more 2's than 3's
etc
However, when earthquakes get to be less than about
5.5 they are too small for our networks to record
and locate all of them. Some are located, but some
are missed. The smaller the magnitude, the more are
missed. Thus, although there are many more 4's than
5's, the catalog contains more 5's than 4's.
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