Comprehensive Geology and Meteorology: Hurricanes, Floods, Fires, and Space

Hurricane Development Requirements

Needs warm ocean water of at least 80 degrees Fahrenheit and low vertical wind shear and moist air and a pre existing weather disturbance

Northern Hemisphere Hurricane Rotation

Storms rotate counterclockwise due to the Coriolis effect

Tropical Cyclone Progression

Organized by increasing strength from tropical disturbance to tropical depression to tropical storm and finally hurricane

Saffir Simpson Scale

A scale from category 1 to 5 used to estimate potential property damage based on a hurricane's sustained wind speed

Base Level

The lowest point to which a stream can erode its channel often represented by sea level

Floodplain

The flat land area surrounding a stream that is subject to periodic flooding

100 Year Flood Probability

The statistical 1 percent chance that a flood of a specific magnitude will occur in any given year

Hydrograph

A graph showing the rate of flow or discharge of a stream over a specific period of time

Hydrograph Limbs

The rising limb represents the rapid increase in discharge after rainfall while the falling limb shows the slower return to base flow

Channelization Effects

Straightening a channel increases the slope and water velocity which can lead to increased erosion downstream

Flood Frequency

Small floods occur frequently with short return periods while large floods are rare with long return periods

Flash Flood Danger

These events are the leading cause of weather related deaths in the US with many fatalities occurring in vehicles

Fire Triangle

The three essential components for fire which are fuel and oxygen and heat

Topographic Slope and Fire

Wildfires travel much faster upslope because the heat rises and preheats the fuel above the flames

Pyrolysis

The chemical decomposition of organic fuel by heating that occurs before actual combustion

Crown Fires and Ladder Fuels

Ladder fuels allow fire to climb from the ground into the forest canopy to create dangerous crown fires

Flashy Fuels

Grasses and shrubs containing volatile oils are considered fast burning or flashy fuels

Mass Movement and Slopes

Steepening a slope beyond the angle of repose increases the likelihood of failure

Mass Movement Speeds

Rockfalls and debris flows are among the fastest while soil creep is the slowest example

Catastrophic Subsidence

Occurs when acidic groundwater dissolves limestone to create caverns that eventually collapse into sinkholes

Slope Failure Triggers

Common triggers include heavy rainfall and earthquakes and oversteepening and removal of vegetation

Dams and Sand Supply

Dams trap sediment behind them which starves downstream beaches of their sand supply

Groin Effects

These structures trap sand on the up-drift side but cause increased erosion on the down-drift side

Wave Velocity Controls

In shallow water the velocity of a wave is primarily controlled by the depth of the water

Longshore Drift

The movement of sand along a beach caused by waves hitting the shore at an angle

Wave Refraction

The bending of waves as they approach the shore which concentrates energy on rocky headlands

Seasonal Beach Changes

Beaches are typically wider with a berm in the summer and narrower with offshore bars in the winter

Rare Earth Craters

Earth has fewer visible impact craters than the moon because of plate tectonics and erosion and atmospheric shielding

Space Object Definitions

Asteroids are rocky bodies while comets are icy and meteors are the streaks of light seen when debris enters the atmosphere

Asteroid Belt Location

The region of the solar system located between the orbits of Mars and Jupiter

Comet Tails and Solar Wind

A comet's tail always points away from the sun because it is pushed by the solar wind

Finding Meteorites

The best place to find them is Antarctica because they are easily spotted against the ice and concentrated by glacier movement

Halley's Comet

A famous short period comet that is visible from Earth every 76 years