As prescribed by Paulina Constancia

Queries on QUAKES 1: What causes earthquakes?

Welcome to a new week here on DDoA! On October 15, the island of Bohol and my hometown of Cebu in the Philippines were hit by a magnitude 7.2 earthquake. It’s been 2 weeks and they continue to feel aftershocks. Boholanos and Cebuanos are not used to earthquakes and most folks do not know what to do, where to go or how to proceed once the tremors have finally stopped. Since most Filipinos are Christians, the first question that comes to mind is “what is God trying to tell us?” And many will respond, “man has become so sinful and this is God’s way of reminding us to repent, pray and be closer to Him.”
This week is dedicated to learning more about earthquakes: the myths and facts of this sudden shaking of our world. Ancient folks have tried to explain them, scientists continue to try to predict and measure them. In the Philippines, many live in fear of the next big one to strike and the rest just want to go about their lives as usual: resigned to fate, believing that when it’s time to go-it’s time to go.

What causes earthquakes? 

A. According to Myths & Folklore

As I researched about beliefs and explanations in different cultures I chanced upon CERI (Center for Earthquake Research and Information) in Memphis. They provide a wealth of curious information about how earthquakes are explained in different countries & cultures. Here are some of them:

Kamchatka, Siberia, Russia
A god named Tuli drove an earth-laden sled pulled by flea-infested dogs: when the dogs stopped to scratch, the earth shook.

Image Source
Mongolia, China

A gigantic frog which carried the world on its back, twitched periodically, producing slight quakes.
Whenever their god visited the earth to count how many people were there, his footsteps caused earthquakes. To shorten his task, the people ran out of their houses to shout “I’m here, I’m here!” (incorporating in their myth, the wisdom of leaving their flimsy houses during an earthquake).
A giant catfish lived in mud beneath the earth. The catfish liked to play pranks and could only be restrained by Kashima, a god who protected the Japanese people from earthquakes. So long as Kashima kept a mighty rock with magical powers over the catfish, the earth was still. But when he relaxed his guard, the catfish thrashed about, causing earthquakes.
The god Kashima holds down the catfish with the Kaname rock
Attack on the catfish from the Edo period
How earthquakes are explained in Philippine mythology:


Bernardo Carpio is a legendary figure in Philippine mythology who is said to be the cause of earthquakes. There are numerous versions of this tale. Some stories say Bernardo Carpio is a giant, as supported by the enormous footsteps he has reputedly left behind in the boondocks of Montalban (now Rodriguez), Rizal. Others say Bernardo was the size of an ordinary man. One  version says that Bernardo Carpio demonstrated unusual strength, even as a child. As a result, the parish priest who baptised him suggested that his parents name him after the Spanish legendary hero Bernardo del Carpio. This became a foreshadowing of the legendary life Carpio himself would lead.” (Source) However, all versions agree he had muscle might that was akin to that of strongman Hercules from ancient Greek lore. The legend’s basic plot is that Bernardo Carpio, a being of great strength, was trapped between two great rocks in the mountains of Montalban. Some versions say he is keeping the big boulders from crashing into each other, and other versions say he remained trapped, and is still trying to break free to this day. Whenever earthquakes occur, old folks believe it is caused by the one and only Bernardo Carpio – stretching those gigantic shoulders. Info Source
The tale of Bernardo Carpio can be considered an etiological myth which explains the occurrence of Earthquakes. Interestingly, the area which hosts the legend of Bernardo Carpio is also home to the West Valley Fault System (formerly called the Marikina Valley Fault System). 
Read more on Wikipedia

Don’t believe everything you hear about earthquakes…
Here are 10 earthquake anecdotes 
that aren’t exactly the stuff of modern science…
(Info from the California Department of Conservation)

Myth #1: Dogs and other animals can “sense” when an earthquake is going to strike. 
The truth is that..  It’s impossible to determine whether a dog is behaving in an unusual manner because it smells an earthquake coming or a cat across the street. Changes in animal behavior sometimes have been observed prior to earthquakes, but that behavior is not consistent, and sometimes there’s no perceptible behavior change prior to an earthquake. 


Myth #2: Earthquakes occur during “earthquake weather.”
The truth is that..   The common misconception that earthquakes occur during hot and dry weather dates to the ancient Greeks. Earthquakes take place miles underground, and can happen at any time in any weather.

Myth #3: Big earthquakes always occur early in the morning. 
The truth is that..   Just as earthquakes don’t care about the weather, they can’t tell time. (In California for example: The 1940 Imperial Valley quake was at 9:36 p.m., the 1989 Loma Prieta quake at 5:02 p.m. ) People who perpetuate the time and weather myths tend to remember the earthquakes that fit the pattern and forget about the ones that don’t.

Myth #4: The ground can open up and swallow people. (You’ve seen the image in books, movies and TV shows.)
The truth is that’s..  not how it works. If a fault could open up, there wouldn’t be any friction. Without friction, there’s no earthquake. But earthquakes cause settling and other ground deformation that can include open fissures into which people, cars, etc., can fall.

Myth #5:The safest place to be in an earthquake is under a doorway. 
The truth is that’s..  true only if you live in an unreinforced adobe home. In a modern structure the doorway is no stronger than the rest of the building. Actually, you’re more likely to be hurt (by the door swinging wildly) in a doorway. And in a public building, you could be in danger from people trying to hurry outside. If you’re inside, get under a table or desk and hang on to it.

Myth #6: Small earthquakes keep big ones from happening. 
The truth is that.. Each magnitude level represents about 31.6 times more energy released. It takes 32 magnitude 3s to equal the energy released in a magnitude 4, 1,000 magnitude 3s to equal a magnitude 5 … and a billion magnitude 3s to equal a single magnitude 9. So while a small quake may temporarily ease stress on a fault line, it does not prevent a large temblor.

Myth #7:The magnitude of an earthquake determines whether disaster assistance is forthcoming. 
The truth is that..  A magnitude 7 quake in the middle of the desert is likely to do less damage than a magnitude 6 in downtown Los Angeles or San Francisco. It is the magnitude of the damage, not the earthquake, which determines the level of response.

Myth #8: If there are good building codes, then the city has good buildings. 
That’s true — provided you’re talking about buildings constructed under current building codes. In the case of older buildings, retrofitting — bringing the building up to modern standards — is up to the building’s owners. (In the Philippines, there are plenty of buildings which were built under older codes.

) Learn about 10 Technologies that Help Buildings Resist Earthquakes
Myth #9: Earthquakes are becoming more frequent. 
The truth is that.. Research shows that earthquakes of magnitude 7.0 or greater have remained fairly constant throughout the century and have actually decreased in recent years. However, since there are a greater number of seismological centers and instruments capable of locating many small earthquakes that went undetected in earlier years, it may seem as if there are more.

Myth #10:There’s nothing I can do about earthquakes, so why worry about them?
It’s true that… earthquakes can’t be stopped, but you can be prepared. You can put together an earthquake kit (food, water, flashlight, etc.), practice “drop, cover and hold on” drills at home with your family and at work, and develop an earthquake plan (where would you meet family members if you weren’t together when an earthquake hit?).

Additional  Myth: Earthquakes are ‘all natural’, man’s activities cannot trigger a quake.
The truth is that..  The vibrations of the Earth’s surface we call earthq­uakes are typically natural occurrences. They’re most often caused by the shifting of plates of rock under the surface of the Earth. These plates move along fault lines, which are places where the otherwise solid rock of the Earth’s crust has cracked. When the plates slide against each other or away from each other, the Earth vibrates violently.

Less often, earthquakes are caused by natural occurrences like volcanic eruptions. But vibrations felt at the surface of the Earth can also result from Earth-shaking, man-made events like underground bomb testing and mine collapses — and the filling and emptying of dam reservoirs.

It’s easy to see how an underground explosion can shake the Earth. But a dam? A dam is just holding back water. How can that cause an earthquake?  Read this article on “How Stuff Works” to learn how a dam — and more specifically its reservoir activity — can trigger a quake, and you’ll find out whether dams have caused earthquakes and other “natural” disasters in the past.” Info Source

Read this article “Can Humans Cause Earthquakes?” on LiveScience

B. According to Scientific Evidence

“Once every 30 seconds somewhere in the world the ground shakes. The shaking is called an, “earthquake.” The estimates are that there are about 500,000 detectable earthquakes a year, 100,000 of those can be felt, and about 100 of them cause damage. Wow!!! Let’s find out why the earth is, “All shook up!”Read more on  idahoptv.org

Why Do Earthquakes Occur?
Info & Image Source

The earth’s crust is broken up into many rocky plates, like pieces of a puzzle. These plates are constantly moving, albeit very slowly, because of the earth’s molten mantle underneath. As the plates move past each other, along fault zones, they sometimes get caught and pressure builds up. When the plates finally give and slip due to the increased pressure, energy is released as seismic waves, causing the ground to shake. This is an earthquake.

Learn all about earthquakes from The Franklin Institute

Below are some informational videos that I have gathered for you to help you better understand the nature of earthquakes. Choose the appropriate video for yourself (or your audience)


1. What is an earthquake? from MOCOMI Kids

Video Source


2. PLATE TECTONICS – from makemegenius
Video Source


1. How do earthquakes work? from HowStuffWorks
Video source

2. Earthquakes 101 – from National geographic
Video Source

Read The History of Deadly Earthquakes on BBC
Read the list of the Top 10 Deadliest Earthquakes (in terms of loss of human life)on NBC News

Tomorrow on DDoA, we talk about how we can  prepare, survive and recover from an earthquake.
“Earthquake” by Snake Jagger
Print available on fineartamerica
“It takes an earthquake to remind us 
that we walk on the crust 
of an unfinished earth.”
In Sunday Morning, CBS  T V, 23  Jan.
Quote Source

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


This entry was posted on October 28, 2013 by in Care, Communicate, Teach and tagged , , .
%d bloggers like this: