(9) Planet Blue
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Studying Alaska's ice and snow to track climate change
Snow
Snow is a form of precipitation. Snow is formed when the water vapor in the clouds turn into tiny ice crystals. It is formed in the atmosphere at temperatures below freezing point.
Fact Scope
• Flurries are short-period snowfalls.
• Coarse, granular wet snow is also known as corn.
• Powder is freshly fallen, uncompacted snow.
• A snowstorm is a heavy storm of snow for a relatively long period.
• A snow squall is a very intense snowstorm for a brief period of time.
• Slush is snow which partially melts upon reaching the ground.
• Penitentes are tall blades of snow and spiked ice found at high altitudes.
• Freezing rain is rain that freezes on impact with a sufficiently cold surface.
Blizzard
A blizzard is a long-lasting snowstorm, where visibility is reduced to less than 3.2 feet.
Snowflake
Snowflakes are a collection of ice crystals.
Weather and Climate
Weather is the state or condition of the atmosphere of a place that exists over a short period of time. It is characterized by change in temperature, wind, atmospheric pressure and the rainfall of a place at any given time. Climate is the average weather of a place over a period of several years. Different places have different climates. The climate of a place can be affected by some major factors such as latitude, altitude, and distance from the sea.
Fact Scope
• Weather occurs mostly in the troposphere.
• A barograph is a device used to measure air pressure.
• An anemometer is a device used to measure wind speed.
• There are about 11,000 weather stations in the world.
• In 1648 Blaise Pascal discovered that atmospheric pressure decreases with height.
• Benjamin Franklin observed the link between volcanic eruption and weather.
• TIROS-1, the first successful weather satellite, was launched in 1960.
• Francis Beaufort and Robert Fitzroy are credited with the birth of weather forecasting as a science.
Meteorology
Meteorology is the study of weather and climatic conditions.
Factors Affecting Weather
The three key factors that determine weather conditions are air temperature, air pressure, and humidity.
Flood and Drought
A flood is the overflowing of water over areas that are normally dry. A flood generally occurs because of heavy rainfall, onshore waves, or rapid snow melting. Crops and people are greatly affected by floods.
A drought is a condition of no rainfall with extreme dry weather. It occurs for a long period, sometimes for months or years, wiping out all plant and animal life. Severe droughts generally occur in deserts and areas bordering deserts.
Fact Scope
In the last 2,000 years, the Yangtze River in China has flooded more than 1,000 times.
• In 1970 the Aswan High Dam was constructed to stop the annual floods of Nile River.
• A meteorological drought is drought caused by prolonged periods of less than average rainfall in a specific region.
• An agricultural drought is caused when there is insufficient moisture for crop production.
• A hydrological drought is caused when water reserves in the lakes and reservoirs fall below normal.
• The Great Leap Forward famine that occurred in 1958–61 in China is regarded as the largest famine of all time.
China's Sorrow
Hwang Ho or “Yellow River” is called “China's sorrow,” because it has caused more destruction than any other river in the world.
• In the last 2,000 years, the Yangtze River in China has flooded more than 1,000 times.
• In 1970 the Aswan High Dam was constructed to stop the annual floods of Nile River.
• A meteorological drought is drought caused by prolonged periods of less than average rainfall in a specific region.
• An agricultural drought is caused when there is insufficient moisture for crop production.
• A hydrological drought is caused when water reserves in the lakes and reservoirs fall below normal.
• The Great Leap Forward famine that occurred in 1958–61 in China is regarded as the largest famine of all time.
Gift of the Nile
For thousands of years, the Egyptians referred
to the annual flooding of Nile River as the
“Gift of the Nile.”
Earthquake
An earthquake is a sudden vibration of the planet’s surface. The movements of tectonic plates deep inside Earth cause earthquakes. Earthquakes can last from a few seconds to a few minutes. They can be very mild or cause great destruction.
Charles Richter, in collaboration with Beno Gutenberg, developed the Richter scale in 1935.
Richter Magnitudes
Earthquake Effects
Less than 2.0 Micro-earthquakes, not felt.
2.0–2.9 Generally not felt, but recorded.
3.0–3.9 Often felt, but rarely causes damage.
4.0–4.9 Noticeable shaking of indoor items, rattling noises. No significant damage.
5.0–5.9 Can cause major damage to poorly constructed buildings over small regions. At most, slight damage to well-designed buildings.
6.0–6.9 Can be destructive in areas up to about 99 miles across in populated areas.
7.0–7.9 Can cause serious damage over larger areas.
8.0–8.9 Can cause serious damage in areas over several hundred miles across.
9.0 or greater Devastating in areas several thousand miles across.
Seismic Scale
The seismic scale is used to measure and compare the relative severity of earthquakes.
Richter Scale
The Richter magnitude test scale or Richter scale is used to assign a single number to quantify the size of an earthquake.
