Uploaded by Alesia Arbitrio

Predicting Natural Hazards PowerPoint

Measuring and Predicting
Natural Disasters
• Why is it important to learn about and be able
to predict and prepare for natural disasters?
– Analyze and interpret data on natural disasters to
forecast future events
– Explain how technology can be used to predict
and prepare for natural disasters.
– We will discuss technology that allows natural
disasters to be measured and predicted.
– We will discuss your opinions on an article about
government mandated evacuation for a natural
Why its important to measure and
predict natural disasters
• Engineers must understand the causes and
behavior of our planet’s natural forces so they
can help people survive natural disasters.
• They design devices that help us minimize,
eliminate, or predict the effects of natural
• Detecting, predicting, and warning about
natural disasters help populations evacuate
and/or seek shelter.
How engineers measure and predict
natural disasters
• Engineers design mountain, ocean, earth, and
atmospheric monitoring devices.
• They design weather instruments, radar, and
satellites to collect data and make predictions.
• Sometimes engineers make devices that
trigger smaller hazards in order to prevent
larger ones.
Preventing Avalanches
• https://www.youtube.com/watch?v=B0RWLx
• Technology: No method to predict
• Prevention:
– Avalanche mortars are designed by engineers to
trigger small avalanches before enough snow
builds up to cause a catastrophic avalanche.
– The explosion shakes the snow loose from the
slope, causing a small avalanche that will cause
much less damage than a large avalanche would.
Avalanche Mortar
Detecting Tsunamis
• Technology: Tsunamis can be detected.
– Engineers design special buoys (floating devices)
that can be left far out at sea to detect tsunami
waves early.
– This gives time for coastal areas to be evacuated.
– Sensors placed on the ocean bottom can detect
even small tsunamis.
– Sensor information is sent to the buoys, then to
satellites that then send the information to
tsunami centers.
– This system collectively is known as DART (deepocean assessment and reporting of tsunamis)
Detecting Tsunamis
Detecting Earthquakes
• Technology: Earthquakes can be detected and
– The most common way of detecting anf
measuring earthquakes is a seismometer (makes a
printout called a seismograph).
recording earthquakes
Detecting Earthquakes
• Seismometer: device used to detect vibration
in the Earth’s surface
– Can detect earthquakes that people can’t even
– Are often placed near fault lines to detect very
small earthquakes to help predict when a large
earthquake might occur
Measuring Earthquakes
• A. There are at least 3 different
measures for rating earthquakes.
• B. Three methods for measurement:
• 1. Mercalli Scale
• 2. Richter Scale
• 3. Moment Magnitude Scale
Mercalli Scale: Rates earthquakes on
the level of damage at a certain
Richter Scale
Moment Magnitude Scale (MMS)
Each level of magnitude is about 32 times more than the last.
Comparing Magnitudes
• Earthquake with a magnitude of 6 on
Richter Scale?
• Moderate damage
• 10 times the energy of a Magnitude 5
• Earthquake with a Magnitude of 6 on
the MMS?
• Moderate damage
• 32 times the energy of a Magnitude 5
Detecting Tornadoes and Hurricanes
• Technology: Tornadoes and Hurricanes can be
– Engineers created Doppler radar stations that are
able to detect approaching thunderstorms.
– Doppler radar sends out pulses or radio waves,
then measure how long it takes the waves to
bounce off objects (such as hail or rain) and return
– This information can help scientists determine size
of the storm, direction it’s moving, and its
Detecting Tornadoes and Hurricanes
Detecting Tornadoes
• Tornado spotters are also used to activate
tornado warnings.
Measuring Tornadoes
• Tornado intenisty is measured on the Fujita
• Based on the damage the tornado inflicts on
human built structures and vegetation
Measuring Tornadoes
Measuring Hurricanes
• Hurricanes are classified as category 1 through
category 5 based upon their sustained wind
• The scale used is the Saffir-Simpson Hurricane
Wind Scale.
Measuring Hurricanes
Predicting Volcanic Eruptions
• Technology: Volcanic eruptions can be predicted
– One indication that a volcano is about to erupt is that
the volcanic mountain grows larger as magma moves
toward Earth’s surface.
– Though this change is difficult to notice because the
growth is so small and takes so long, engineers have
developed tiltmeters that can detect small changes in
the shape of volcanoes.
– Tiltmeters are placed directly on the side of
volcanoes to help predict upcoming eruptions.
Predicting Volcanic Eruptions
Monitoring Floods
• Technology: Floods can be monitored with
– Floods are monitored with a water gauge.
– A water gauge is a vertical post marked with water
depths and placed in rivers and streams that flood often.
– If the water rises over a certain level on the gauge,
neraby communities may be evacuated to prevent loss
of lives.
– Some fancier water gauges automatically relay
information to local data centers.
Monitoring Floods
• Should the government have the power to
make people evacuate?