Types of Fossils and Their Formation

Fossils

• Fossils are molds of plants and animals that lived thousands of years ago, and are divided into two types: trace fossils and body fossils.
• Trace fossils are evidence of animal activity that is preserved, while body fossils are remains of a plant or animal that were trapped under dirt and preserved over a long period of time.
• Fossils are usually found in sedimentary rock, and have been found on all continents, with a higher concentration in North and South America, and Asia.
• Some fossils are found in amber, which is a resin that preserves animals, and coprolite, which is fossilized animal poop.

The Water Cycle

• The water cycle is a set of repeated events that involve evaporation, condensation, precipitation, and collection.
• Evaporation occurs when water is warmed up and turns into a gas.
• Condensation occurs when water gas gets cold and turns back into a liquid.
• Precipitation occurs when water falls back to the earth.
• Collection occurs when water is stored in lakes, rivers, oceans, soil, and rocks.

Clouds

• There are four main types of clouds: cumulus, stratus, alto, and cirrus.
• Cumulus clouds are puffy and white, like cotton balls.
• Stratus clouds are flat and white, like sheets.
• Alto clouds are made of water droplets and sometimes ice droplets.
• Cirrus clouds are white and wispy, and come with rain-free weather.

The Atmosphere

• The atmosphere is the circle of gas that surrounds planet Earth, and is divided into five layers: Troposphere, Mesosphere, Stratosphere, Thermosphere, and Exosphere.

Solar Radiation

• Solar radiation is sunlight and energy that comes from the sun and travels to Earth in the form of light waves.
• Light waves come in different forms, vibrate, and have different lengths and energy levels.
• Solar radiation is necessary for living things to survive on Earth, and provides visible light, infrared light, and ultraviolet (UV) light.

Wind

• Wind is the movement of air caused by differences in air pressure.
• The wind blows because the sun heats land faster than it heats water, which causes changes in air pressure.
• Meteorologists use instruments like an anemometer to measure wind speed.
• Wind energy can be captured using wind turbines, which spin like giant pinwheels.

Prevailing Winds

• Prevailing winds are dominant winds in a certain area.
• Wind direction is where the wind is coming from, and wind speed is the measurement of how fast the air is moving.
• Tools for measuring wind speed include an anemometer and the Beaufort scale, which rates wind from 0-12.

Air Pressure

• Air has weight, and because of that, exerts pressure.
• Meteorologists measure pressure to predict the weather.
• In a high pressure area, air molecules are held down, resulting in clear, sunny days.
• In a low pressure area, air and water molecules are able to float high into the sky, resulting in cloudy, rainy days.

Air Masses

• Air masses that stay in a particular area begin to take on the characteristics of the temperature and humidity in that area.
• There are six kinds of air masses, each named after the locations in which they form: maritime tropical, continental arctic, maritime arctic, maritime polar, continental polar, and continental tropical.
• Air masses can move from one area of the world to another because of jet streams, which move from west to east.
• When air masses move, they affect the weather because they take with them the characteristics of their birthplaces.

Cloud Formation

• Clouds can be created for a number of reasons, including convectional lifting, cold fronts, warm fronts, stationary fronts, and occluded fronts.
• Convectional lifting occurs when warm, humid air rises and begins to cool, causing the water vapor to condense into clouds.
• Cold fronts occur when a cold air mass takes over a warm air mass, causing it to go up into the atmosphere.
• Warm fronts occur when a warm air mass takes over a cold air mass, leaving warm air.
• Stationary fronts occur when neither the warm air mass nor cold air mass moves.
• Occluded fronts occur when a cold front is created in a low pressure area.

Tornadoes

• A tornado is a spinning column of air that stretches from a thunderstorm to the ground.
• Tornado winds are very strong, which makes them dangerous.
• Tornadoes form in a thunderstorm when an area of warm air meets an area of cold air, and the winds are blowing in just the right way.
• Tornadoes have struck every single U.S. state, including Hawaii, but the area of greatest concern is Tornado Alley, which includes parts of Texas, Oklahoma, Kansas, and Nebraska.

Hurricanes

• Hurricanes are powerful storms that form over oceans and get their energy from the warm ocean waters.
• Hurricane winds blow at 74 to 200 miles per hour and spin due to the Coriolis effect, which is a force created by the spinning of the Earth.
• The calm area in the center of a hurricane is called the eye.

Thunderstorms

• A thunderstorm is a rainstorm with thunder and lightning.
• Thunderstorms need moisture, unstable air, and lift to form.
• Thunderstorms have three stages: developing, mature, and dissipating.
• They can happen almost anywhere in the world and in any season.
• They can occur at any time of day, although most often in the afternoon and evening.

Lightning

• Lightning is a flash of light produced by electricity when negatively-charged electrons and positively-charged protons collide.
• There are different kinds of lightning, including cloud-to-ground, cloud-to-cloud, intra-cloud, and cloud-to-air.
• Lightning is dangerous, and the best way to stay safe is to get inside a big building and stay away from windows.

Ecosystems

• Ecosystems are specific areas that can be either in water (aquatic) or on land (terrestrial).
• An ecosystem is made up of living organisms and non-living things that depend on each other for survival.
• We also learned about food chains, which include producers, primary consumers, secondary consumers, decomposers, and omnivores.

Energy Transfer

• In order to survive, living things need energy, and energy passes from a producer (which are plants that make their own energy from the sunlight) into herbivores (plant-eating animals), carnivores (meat-eating animals), and omnivores (animals that eat both plants and meat).
• We use food chains to represent a single flow of energy and we use food webs to represent the feeding relationship between many living things within a community.

The Energy Pyramid

• The energy pyramid shows us how energy transfers from one organism to the next on the food chain.

Weather

• Weather is the state of the atmosphere at any given time.
• Weather is affected by the Sun's rays and their interaction with the gases in the Earth's atmosphere.
• Weather has many aspects, including wind, pressure, cloud cover, temperature, and precipitation.

Climate

• Climate is the pattern of weather in an area over a long period of time.
• It's impacted by different factors, including temperature, humidity, distance from bodies of water, wind, the amount and types of precipitation, topography, latitude, and elevation.
• There are five main types of climate: tropical, dry, mild, continental, and polar.

Forecasting

• A forecast is a prediction, or good guess, about the future.
• Weather forecasting is when scientists called meteorologists use many different tools to predict what the weather in the near future will be.
• Meteorologists pay attention to the temperature, air pressure, clouds, and other factors to make their predictions.

Meteorologists

• Scientists who study the atmosphere and predict the weather are called meteorologists.
• They use weather maps to show what the weather forecast will be, and these weather maps are important because they show us how to plan our day and week.
• There are several types of weather maps, such as satellite, precipitation, temperature, front maps, wind speed, and Doppler radar.