Download EARTHQUAKE SEASON: EXPLANATION OF A COMMON MYTH By

EARTHQUAKE SEASON:
EXPLANATION OF A COMMON MYTH
By S. Danielle Hanson with Evelyn Kruis
Severe weather has had devastating
effects on civilizations, from the ancients to
the present, leaving people fearful of the
next event. Perhaps one of the most
unsettling aspects of one of these events is
their unpredictability. As history has
unfolded, there have been many advances in
the understanding of weather. For example,
weather patterns are now being observed as
cyclical and even predictable within a given
geographic location.
Earthquakes come out top of the list
as one of the most volatile phenomena. There have been several attempts to predict earthquakes
in a manner similar to that of predicting the weather.
Aristotle, in a text on earthquake theory, presents a hypothesis on weather that has been
accepted famously for centuries:
“We must suppose the action of the wind in the
earth to be analogous to the tremors and
throbbing caused in us by the force of the wind
contained in our bodies. Again, we must think of
an earthquake as something like the tremor that
often runs through the body after passing water
as the wind returns inwards from without in one
volume. “ -Aristotle
Aristotle thought the earth was like a sponge and that the wind dove into cavernous areas
below the surface. During the windiest seasons, harder wind meant more air was being forced
into the earth. Aristotle reasoned that the process was like that of air within the human body,
more air produced a larger internal tremor. Accordingly, the presence of more wind on the
surface indicated that there would eventually be more of an underground disturbance, resulting in
an earthquake. As a result, windy seasons became known as
earthquake season.
Anaximense of Miletus, added to Aristotle’s
hypothesis by explaining that what the wind does to the earth
can also be done by either a dry or wet season, “the earth
grows dry in time of drought and breaks up, whereas the rain
makes it sodden and destroys its cohesion.” Accordingly,
wind, drought, or rain can cause underground disturbances,
resulting in an earthquake.
S. Danielle Hanson in her lab in Los Angeles
Both these theories have since been disproved. Today, we know that the Earth’s
outermost layer, the crust, moves due to tectonic forces – generally from the convection of the
denser mantle below. This rigid and fractured crust is broken into large sections called tectonic
plates, which are typically 20-30 miles thick.
The boundary at which the plates move past one another
is called a fault zone. Massive amounts of friction (stickiness)
cause the plates to become stuck and then generate lots of strain.
When the friction releases, the moving plates rebound, quickly
sliding past one another. At that moment, a huge amount of
energy is released in the form of an earthquake. Thus
Earthquakes have to do with tectonic forces from deep within
the solid, plastic (moveable) earth, not weather. Weather does
not cause or signify impending earthquakes.
Do not be fooled into thinking you can watch the weather to predict earthquakes. Take
the time now to learn what you can do to be safe in the event of an earthquake in your area. After
all, disasters happen when proper preparation does not.
For starters, log onto www.youngmeteorologist.org and PLAY
THE WEATHER GAME! Let Owlie Skywarn and his friends will lead
you through five severe weather challenges. Together you’ll work to
earn your Young Meteorologist Certificate!
Owlie Skywarn was revitalized by Plan!t Now, an NGO that
assists by educating communities at risk of being negatively impacted by
severe weather events including hurricanes and tropical storms,
flooding, winter storms, earthquakes, fires and man-made disasters about severe weather science
as it pertains to preparedness. Working with public, government, nonprofit and private partner,
we promulgate important information that helps those at risk prepare their families and
communities. For more information visit: http://www.planitnow.org/.