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Ep331: Earthquakes · Kidcast Daily

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  Spin the wheel, let's take a ride.
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  Sports and science bursting from inside a world of wonder open
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  wide. Come on kids, let's amplify kid
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  cats. Daily starts your day.
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  Fun and laughter come your way. Sports and trivia games galore.
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  Hi there. It's Kick Ass Daily, the show
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  that covers everything from outer space to ocean depths,
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  sports superstars to science breakthroughs, all made just for
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  you. Today we are exploring
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  earthquakes. These are sudden shakes of the
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  ground that happen when parts of Earth's outer shell move.
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  The outer shell is called the lithosphere and it is not one
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  solid piece. It is made of large slabs called
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  tectonic plates. These plates move very slowly, a
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  few centimeters each year as they float on softer, hotter
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  rock deeper inside the planet. Most of the time, plates get
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  stuck along their edges. Where they touch, stress builds
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  up. When the plates finally slip,
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  energy releases. That release is an earthquake.
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  Where do these slips happen? They happen on cracks in the
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  crust, called faults. Some faults are long and reach
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  near the surface. Others are deep.
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  When the slip starts below ground, the point where it
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  begins is called the focus. The spot on the surface directly
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  above the focus is called the epicenter.
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  People near the epicenter often feel the strongest shaking.
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  Earthquakes can be small and barely noticed, or strong enough
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  to move buildings and roads. Many small ones happen every day
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  around the world. An earthquake sends out energy
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  in different kinds of waves. The first ones are primary waves
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  or P waves. They are the fastest, so they
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  arrive first. After them comes secondary waves
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  or S waves. They're slower but can cause
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  more side to side and up and down shaking.
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  There are also surface waves that travel along the ground.
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  These can cause long rolling motion that makes objects sway
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  and slide. The order goes P waves, then S
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  waves, then surface waves and that is why you might feel quick
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  jolts followed by stronger motion.
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  Scientists measure earthquakes in a few ways.
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  Magnitude is a number that tells how much energy was released at
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  the source. The moment magnitude scale is
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  commonly used today. It gives 1 number for the whole
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  earthquake. Intensity is different.
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  It describes how strong the shaking feels in a specific
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  place. Intensity can change from
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  neighborhood to neighborhood depending on distance to the
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  epicenter and the type of ground under the buildings.
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  Soft, water rich soil can shake more than Hard Rock.
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  Seismographs are instruments that record ground motion.
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  They draw squiggly lines called seismograms.
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  By looking at these records, scientists can tell when an
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  earthquake started, how strong it was, and how far away it
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  happened. Earthquakes can trigger
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  aftershocks. These are smaller quakes that
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  follow the main one. They happen as the crust adjusts
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  to the new position of the fault.
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  Aftershocks can come minutes, days or weeks later.
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  A small earthquake can have only a few aftershocks.
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  A large earthquake can have many.
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  Sometimes small earthquakes happen before a larger one.
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  Those are called 4 shocks. Not every big earthquake has
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  four shocks, and not every small quake means a bigger 1 is
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  coming. You might wonder what
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  earthquakes can do. They can cause cracks and roads,
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  make shelves, tip over, and in strong cases, damage bridges or
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  buildings. In coastal areas, undersea
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  earthquakes can move the sea floor.
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  When that happens, a tsunami can form, which is a series of large
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  ocean waves that can travel across entire oceans.
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  Warning systems watch for sudden changes in the ocean to alert
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  people who live near coasts. Communities prepare in many
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  ways. Engineers design buildings with
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  features that help them handle shaking.
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  These include strong frames, braces and devices that reduce
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  motion in earthquake prone places.
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  Crews attach heavy objects like water tanks and air conditioning
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  units with sturdy bolts and straps.
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  Utilities add flexible connections to gas lines to
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  reduce leaks. Schools practice earthquake
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  drills. Families pack emergency kits
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  with water, snacks, a flashlight, a radio, spare
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  batteries and a small first aid kit.
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  A simple plan helps everyone know where to meet after a
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  quake. If phones do not work.
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  Here is a yes or no question. Can earthquakes happen far from
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  the edges of tectonic plates? Yes.
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  While many earthquakes happen along plate boundaries, some
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  occur in the middle of plates. These are called intraplate
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  earthquakes. A well known region in the
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  central United States called the New Madrid Seismic Zone had a
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  series of powerful earthquakes in the early 1800s.
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  Other intraplate quakes have happened in Australia and India.
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  Even if a place is far from an ocean trench or a mountain
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  range, old faults inside a plate can still slip.
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  Let's talk about early warnings. In some regions, special sensors
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  detect the first P waves and send alerts before the stronger
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  shaking arrives. Trains can slow down, hospital
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  equipment can switch to safe modes, and people can take quick
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  protective steps. The warning time is short,
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  sometimes just a few seconds, but it can still help.
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  The key is to react fast and follow safety steps.
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  Here is a trivia question for you.
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  In the United States, which scientific agency runs the
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  National Earthquake Information Center that monitors earthquakes
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  worldwide, the United States Geological Survey or USGS?
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  Scientists there collect data from thousands of seismograph
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  stations, share rapid reports and help emergency teams
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  understand what happened. Many other countries have
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  national agencies, too, and global networks share
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  information to improve safety. Now for a quick yes or no
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  question. Do primary waves or P waves
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  travel through liquids, such as Earth's outer core?
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  Yes, P waves move through solids, liquids and gases.
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  Secondary waves, or S waves, move only through solids because
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  S waves do not pass through liquids.
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  Scientists learned that the outer core of Earth is liquid by
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  studying how these waves move and where they do not.
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  Researchers map layers deep inside our planet.
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  Here is another trivia question. How many seismograph stations
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  are needed to pinpoint and earthquakes at the center
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  accurately? Using a method called
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  triangulation? At least three stations.
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  Each station measures how long it took for the P waves and S
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  waves to arrive. The difference in arrival times
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  tells how far the epicenter is from that station.
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  With three distant circles, the spot where they meet is the
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  epicenter. More stations improve accuracy
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  and help confirm the location and depth.
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  Let's add a real life example. Japan, Chile and California sit
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  along active plate boundaries. These places use strong building
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  codes that require steel reinforcement, shear walls, and
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  secure connections. Bridges may include rubber
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  bearings and sliding devices that help them move safely
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  during shaking. In some tall buildings,
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  engineers add tuned mass dampers, which are very heavy
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  weights with special controls that reduce swaying during long
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  lasting waves. These features do not stop
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  earthquakes, but they limit damage and help people stay
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  safer. Now a yes or no question about
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  technology you might carry. Do some smartphones help detect
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  shaking and support earthquake early warning systems In certain
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  regions? Yes, phones contain tiny sensors
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  called accelerometers. When many phones in the same
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  area sense unusual motion at the same time, a system can analyze
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  the pattern and add it to data from dedicated sensors.
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  This does not replace professional seismographs, but
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  it can add extra information very quickly.
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  What should you do if you feel shaking?
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  Drop, cover and hold on. Get down on your hands and knees
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  so you do not get knocked over. Cover your head and neck and if
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  possible, get under a sturdy table or desk.
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  Hold on to the furniture so it stays over you.
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  Stay away from windows, tall bookcases and hanging objects.
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  If you are in bed, stay there and cover your head with a
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  pillow. If you are outside, move to an
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  open area away from buildings, trees and power lines.
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  If you are in a car, pull over in a safe spot and set the
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  parking brake. After the shaking stops, check
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  for hazards like gas smells or fallen power lines and follow
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  local instructions. Did you know that the largest
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  earthquake recorded by instruments had a magnitude of
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  about 9.5 in Chile in 1960? It caused damage across southern
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  Chile and generated A tsunami that crossed the Pacific Ocean.
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  Another very large one struck Alaska in 1964 with a magnitude
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  of about 9.2. These events are rare.
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  Most earthquakes are much smaller and are only felt nearby
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  or not at all. Here is one more yes or no
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  question. Can scientists predict the exact
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  day and time of a future earthquake?
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  No Scientists can estimate the likelihood of earthquakes in a
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  region over years or decades by studying faults and past
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  activity. They can also give alerts once
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  an earthquake has started using early warning systems.
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  But a precise prediction with a date, time, and location is not
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  possible with current science. Before we wrap up, let's review.
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  Earthquakes happen when stress along faults in Earth's crust
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  releases. The focus is where the slip
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  starts underground, and the epicenter is the point on the
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  surface above it. Energy travels as P waves, S
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  waves, and surface waves. Magnitude measures total energy,
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  while intensity describes shaking out of place.
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  Seismographs record motion and networks use data to find
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  locations and send reports. Earthquakes can cause
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  aftershocks, and under the ocean can help create tsunamis.
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  Communities prepare with strong buildings, drills, and safety
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  plans. You can prepare by learning
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  drop, cover and hold on and by keeping an emergency kit.
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  We also learned that earthquakes can happen inside plates.
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  P waves can travel through liquids, but S waves cannot.
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  At least three stations are needed to locate an epicenter.
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  The USGS runs a major monitoring center in the United States, and
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  even smartphones can help add data for early warnings.
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  Stay curious, stay ready, and keep exploring the amazing
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  science of our planet. Grab your breakfast.
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  Feeling fine? Adventures waiting?
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  Don't be late, Today's the day we celebrate.
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  Kick Ass Daily starts your day.