Earthquakes Alison Isabella

100 %
0 %
Information about Earthquakes Alison Isabella

Published on July 3, 2009

Author: sherberts



WALT find out about and develop an action plan for a natural disaster with a NZ focus. WASW we include information on the science behind the disaster, diagrams, historic information, an animation/model/flip file/movie of the disaster in action, an action plan and a bibliography.

WHAT IS AN EARTHQUAKE? The surface of our planet is not exactly a complete shell, but is made up of big pieces, kind of like a jig-saw puzzle, these are called tectonic plates. Tectonic plates are always moving around. Tension builds up as they scrape over, under or past each other. In some places the movement between the plates happens all the time, causing lots of small or gentle earthquakes. Other areas, where the movement is not that constant, are horizontal to stronger earthquakes separated by longer stages of time. In other words the tectonic plates move around each other causing the earth to shake. The place where they slip is called the fault or fault plane Sometimes tension can be built up for hundreds or thousands of years before it's released in a great quake. Earthquake-prone areas like San Francisco and Los Angeles continue to be at risk from a large quake.

What causes earthquakes and where do they happen? As most of you know there are four layers of the earth… The Inner Core, the Outer Core, The Mantle and The Crust. The crust and the top of the mantle make up a thin layer on the surface of our planet.  But this layer is not all in one piece – it is made up of many pieces like a jig-saw covering the surface of the earth. The plate boundaries are made up of many faults, and most of the earthquakes around the world occur on these faults.  Since the edges of the plates are rough, they get stuck while the rest of the plate keeps moving.  Finally, when the plate has moved far enough, the edges unstick on one of the faults and there is an earthquake. This is a picture of some tectonic plates

How are earthquakes recorded? Earthquakes are recorded by machines called seismographs. The recording they make is called a seismogram..The seismograph has a base that is set firmly in the ground, and a heavy weight that hangs free.  When an earthquake causes the ground to shake, the base of the seismograph shakes too, but the hanging weight does not.  Instead the spring or string that it is hanging from absorbs all the movement.  The difference in position between the shaking part of the seismograph and the motionless part is what is recorded. This is picture of a recording on a seismograph This is a picture of a seismograph

The Richter Scale This instrument is used to measure the magnitude of earthquake. The scale, more better known as the Richter magnitude test scale, ranges from 0 to over 8.0. It is a logarithmic scale which means each unit increase on the scale corresponds to an absolute increase by an order of magnitude, or factor of 10. Earthquakes less than about 2 on the Richter scale are barely anything as they can barely even be measured, much less felt. An earthquake isn’t fit to be in the news until it hits about 5. At magnitudes of 7 or 8 the damage can be deadly. The magnitude of an earthquake is measured using a seismometer. The original Richter scale was based on a one type of seismometer. It consists of a stable frame, a weight held in place by inertia(regard to effort), vibration-dampening springs to prevent long-term oscillations, and a way of measuring the displacement of the weight from the reference point. The earthquake's strength is measured by the degree to which it causes the weight to be displaced. Because the seismometer is rarely at the epicenter of an earthquake, calibration techniques are used to determine what the displacement would have been if it were actually located there. Earthquakes cannot be measured very well using the Richter scale when the magnitude is above about 8.3.

On one of the websites we found lots of historical earthquakes but we chose this one… This one happened in 1987. It is called the Edgecumbe earthquake. It happened on the 2nd of March at 1:35pm. The magnitude was 5.2 and it happened in Bay Of Plenty (around that region) It even cut off some power forcing people outdoors. After a few minutes another earthquake struck but this time it was stronger with a magnitude of 6.3. It happened at 1:42pm. The second quake was in the middle of the north of Edgecumbe. There were four aftershocks with greater than five in the next six hours! Some smaller aftershocks were left felt for weeks! The most spectacular effect of the Edgecumbe earthquake was the 7-kilometre-long rift that appeared across the Rangitāiki Plains – the Edgecumbe Fault. Click on this to go to a website to see some earthquakes that happened in NZ

What to do when there is an earthquake You need a survival kit that will last for 72 hours. This applies to any natural disaster. Before the disaster: ~Practice the DROP, COVER and HOLD with your family ~Identify places around your home that are safe ~Get your parents to FIX, FASTEN and FORGET items During the disaster: ~DROP, COVER and HOLD ~Stay where you are until the shaking stops ~Don’t try to run outside (if inside) After the disaster: ~Listen to instructions from the radio ~Stay calm and help others ~Remember the safety rules

Action plan ~ Part 1 It could be something like… Family name and phone number:_________ Police:_____ Fire:_____ Ambulance:_____ Doctor:__________________ Other friends/family:

Action plan ~ Part 2 In an emergency… ________will___________________________________ ________will___________________________________ ________will___________________________________ If we get separated we will meet at:___________ In an earthquake we will Drop, Cover and Hold under shelter. In an emergency when we need to get out of the house we will take our survival kit, radio and stay calm. Take only valuable and important small items. Leave big pets behind free, we know it’s sad but you have to. Make sure you don’t forget to fix, fasten and forget items.

Emergency items ~Torch with spare batteries ~Radio with spare batteries (check all batteries every 3 months) ~A change of clothes for all family members (wind and waterproof clothing, sun hats, and ~strong outdoor shoes) ~First aid kit and essential medicines ~Blankets or sleeping bags ~Pet supplies ~Toilet paper and large rubbish bags for your emergency toilet ~Face and dust masks Food and water for at least three days ~Non-perishable food (canned or dried food) ~Bottled water (at least 3 litres per person, per day for drinking) ~Plan how to get water for washing and cooking (check your hot water cylinder, pond, toilet cistern if it is free of chemicals) ~A primus or gas barbeque to cook on ~A can opener ~Check and replace food and water every twelve months. Supplies for babies and small children ~Food, formula and drink ~Change of clothing and nappies ~Toys or favourite activity

Getaway kit.. Family documents ~Drivers licenses and passports ~Financial info ~Family photos Personal items ~Toiletry ~Hearing aids, glasses, mobility aids for senior citizens or vulnerable family members

Types of earthquakes Interplate earthquakes occur along the three types of plate boundaries: (1) mid-ocean spreading ridges, (2) subduction zones, and (3) transform faults. Mid-ocean spreading ridgesMid-ocean spreading ridges are places in the depths of the ocean valley where the plates move away from each other. As the plates separate, hot lava from mantle rises between them. The lava cools gradually, contracts, and cracks, creating faults/fault planes. Along the faults, chunks of rock break and slide down away from the ridge, creating earthquakes. Near the spreading ridges, the plates are thin and weak. The rock hasn’t cooled completely, so it is still somewhat flexible, because large forces cannot build, and most earthquakes near spreading ridges are shallow.Subduction zones Subduction zones are places where two plates collide into each other, and the edge of one tectonic plate pushes under the edge of the other in a process called subduction. Because of the outline in these places, many of the faults are reverse faults. About 80 per cent of big earthquakes occur in subduction zones surrounding the Pacific Ocean. In these areas, the plates under the Pacific Ocean are diving beneath the plates carrying the continents. The crushing of the colder ocean plates beneath the continental plates creates huge forces that are released in the world's largest earthquakes.

Faults are divided into three main groups. Reverse fault-when two plates crash and one moves on top of another; normal fault -when two plates move apart; and strike-slip or lateral - when two plates slide past each other. In a normal fault, the block of rock on the upper side of the sloping wound slides down. In a reverse fault, the rock on both sides of the fault is greatly compressed. The push forces the upper block to slide upward and the lower block to thrust downward. In a strike-slip fault, the fracture extends straight down into the rock, and the blocks of rock along the fault slide past each other horizontally. Transform plate boundaries Transform plate boundaries is when plates slide horizontally against each other, neither create nor destroy lithosphere (The outer part of the earth, consisting of the crust and upper mantle, approximately 100 km {62 mi.} thick). However, at these boundaries, or transform fault planes, powerful earthquakes can occur. Although the tremendous force of plates scraping against each other is responsible for many earthquakes, we humans can cause them as well. In some areas, big earthquake damage is the result of blending of soil. In the right conditions, the violent shaking from quake will make loosely packed powder and soil behave like a liquid. When a building or house is built on this type of powder, liquefaction will cause the structure to collapse more easily. Highly developed areas built on loose ground material can suffer severe damage from even a relatively small earthquake. Liquefaction can also cause severe mudslides.

Bibliography picture picture picture   Get ready, get thru civil defence booklet An emergency plan could save your life civil defence booklet

Hope you enjoyed it!!

Add a comment

Related pages

Isabella m - Documents

Isabella Braveheart of France by Colin Falconer Comments. ... Earthquakes Alison Isabella. Adam - Isabella - Cleric Level 3. Queen Isabella I of Castile.
Read more

Earthquake in Haiti - Images | Alison Wright Photography

Earthquake in Haiti (33 images) ... 2010 earthquake. Alison with Peterson ... 2010 earthquake. Maria Isabel Moreno ...
Read more

Modified Drinking Straw (LifeStraw) by Alison Dana Isabel ...

Modified Drinking Straw (LifeStraw) ... Alison Dana Isabel Liam on 23 May 2014 ... (earthquakes, floods) removes bacteria
Read more

Isabella Colvin 1904 - ? - Kete West Coast

Isabella recalls the 1918 flu epidemic and 1929 earthquake. ... Alison Cordery. created Isabella Colvin 1904 ...
Read more

Help Allison/Anthony Quattrocchi by Allison Marie - GoFundMe

Help Allison/Anthony Quattrocchi by Allison Marie - Isabella (a twin) was born December 29, 2015. We (mom and dad) had found out that Isabella had ...
Read more

Allison M. Winkler | LinkedIn

View Allison M. Winkler’s professional profile on LinkedIn. LinkedIn is the world's largest business network, helping professionals like Allison M ...
Read more