What supercontinent broke apart to create the continents we know today?
It is believed that similar fossil discoveries across continents can be attributed to Pangea's existence. The supercontinent is believed to have broken apart around 200 million years ago.
What is the longest river in the world?
The Nile River
It is 4,258 miles long and spans 11 African countries.
What is the deepest area found in any of the world's oceans?
The Mariana Trench
Located in the Pacific Ocean, the Mariana Trench is 6.8 miles deep.
What are the three layers of the Earth's interior?
Crust: The outermost layer of the Earth, this hard outer shell is made up of rock and is anywhere from a few miles to 20 miles thick.
Mantle: The upper and lower mantle are located below the crust and are made up of solid and molten rock. The thickest of the 3 layers, the mantle is approximately 1,800 miles thick.
Core: The core of the Earth is separated into two parts: outer and inner. The outer core is comprised mostly of liquified iron and nickel, and spans 1,400 miles. The inner core of solid, hot iron and nickel is about 750 miles in diameter.
What is an archipelago?
An archipelago is a chain of islands.
It is common for archipelagos to be volcanic. Indonesia is identified as the largest archipelagic state. Other well-known archipelagos include Japan, the Phillipines, New Zealand, and the British Isles. Some well-known United States archipelagos include the Hawaiian Islands, the Outer Banks, and the Florida Keys.
What causes a volcano to form? What are the three types of volcanos?
Volcanos are caused by shifts in the Earth's tectonic plates or hot spots that flare up underneath the Earth's crust. Volcanos can be categorized in three ways:
- Active: Has erupted recently or is expected to in the future.
- Dormant: Has not erupted recently; may or may not erupt again in the future.
- Extinct: Not likely to erupt again.
What are the most common gemstones?
The most common gems include:
What is an amber fossil?
An amber fossil is formed when an organism dies and is trapped in tree resin, which hardens and becomes amber over time, preserving the animal inside.
Organisms that would have otherwise decayed, such as early insects and plant life, have been found intact in amber fossils. Although some famous movies and real scientists helped us believe for most of the past 25 years that it may be possible to recover full DNA samples from amber fossils, it is now believed that the chances of such science are close to nil.
What large landform is comprised solely of densely packed layers of ice formed over time?
The largest glacier in the world is Lambert Glacier. Located in East Antarctica, it spans 250 miles and is about 2,500 meters deep.
What is the tallest waterfall?
Angel Falls, located in Venezuela, is the tallest waterfall, with a height of 3,212 feet.
What is the Greenhouse Effect?
When energy from the sun hits the surface of the planet, infrared radiation is reflected back into space. Some of this energy is trapped by greenhouse gases, warming the Earth.
Greenhouse gases in the atmosphere are necessary for life, but elevated levels may result in overheating of the atmosphere (AKA global warming). Electricity generation and transportation are the two most common man-made sources of greenhouse gases. The most important greenhouse gas is carbon dioxide.
What landform is surrounded by water on three sides and connects to land on the remaining side?
Well-known peninsulas include the Arabian Peninsula, Alaska, and Cape Cod, Massachusetts.
Any resource that is able to replenish over time is categorized as a ___ resource.
Renewable resources include wood, wind, and solar energy. Non-renewable resources include fossil fuels such as gasoline and coal, as well as minerals such as copper.
What are the major eras of the Earth and their milestones?
Precambrian: The oldest era, 4,500 million years in length, includes the development of Earth's oceans, early landforms, single-celled organisms, and first multi-celled organisms.
Paleozoic: This era, 291 million years in length, brought the earliest forms of sea life, plants, insects, and eventually early reptiles and amphibians.
Mesozoic: Also known as the Age of Reptiles, this 186 million year period included the dinosaurs, the first birds, and the first mammals.
Cenozoic: The current era, referred to as the Age of Mammals, has spanned 66 million years thus far. Mammals and birds thrive and evolve, including the introduction of the first humans.
What is the difference between hail and sleet?
Sleet is frozen ice pellets that are generally larger than hail. While sleet occurs during winter storms, hail usually is seen during thunder storms and causes much more damage.
What is the composition of the air in Earth's atmosphere?
- 78% nitrogen
- 21% oxygen
- 0.9% argon
- 0.03% carbon dioxide
- trace amounts of other gases including neon, helium, krypton, and xenon
The movement of the Earth's crust and upper mantle in large pieces is known as ___ ___.
The crust and upper mantle make up tectonic plates. As these shift, so do pieces of the Earth and sea. The shifting of these tectonic plates can result in earthquakes, mountain formation, and volcanic eruptions.
What is a biome -- and what are the five major types of biomes?
A biome is a way of classifying major ecosystems.
Biomes are grouped by plant life and climate. There are a variety of biome classification schemes, but the five major types are:
What are the eight levels by which conservationists classify endangered species?
- Extinct in the Wild
- Critically Endangered
- Near Threatened
- Conservation Dependent
- Least Concern
What are the major layers of the atmosphere?
Troposphere: the lowest level of the atmosphere, where weather and clouds form
Stratosphere: the second lowest level of the atmosphere, where the ozone and highest clouds are located
Mesosphere & Thermosphere: the upper layers of the atmosphere that merge with outer space
What are latitude and longitude lines?
Latitude and longitude are part of the coordinate system used to measure and navigate the Earth.
Lines of latitude run parallel to the equator (which divides the Earth into the Northern and Southern Hemispheres), tracing a circle around the Earth measuring how far north or south a location is from the equator.
Lines of longitude run vertically and measure a locations's angle of difference from the Prime Meridian (which runs from the North to the South pole on a globe).
Both latitude and longitude are measured in degrees, minutes, and seconds.
What are some causes of deforestation?
Deforestation is caused by:
- commercial logging
- climate change
- other forms of development
Approximately 36 football fields' worth of forests are lost each minute worldwide.
Is there a difference between magma and lava?
Only a slight difference.
magma refers to what is still underground, but lava is the term used for molten rock that is above ground due to a volcanic or seismic event.
The preserved materials of a deceased organism, commonly bones and teeth, are called ___.
The biggest fossil ever discovered was the skeleton of the dinosaur titanosaur, measuring 130 feet long and 65 feet tall.
What are the steps of the rock cycle?
- When a volcano erupts, lava hardens and forms igneous rocks.
- After a great deal of weathering and displacement, these rocks break down and settle in sediment beds, eventually forming sedimentary rocks.
- As this new rock moves deeper into the Earth, it is exposed to heat and pressure, which changes it into metamorphic rock.
- The process is cyclical because these metamorphic rocks eventually melt to the original state — magma, which will again become igneous rock.
What type of body of water is located where salt water from the ocean meets fresh water from other bodies of water such as rivers?
Estuaries' unique inflow of both fresh and sea water provides a nutrient-rich environment and thriving habitat for a diverse set of species.
Approximately 2/3rds of the world's largest cities are located on estuaries. The human activities around many estuaries have made them among the most threatened ecosystems.
Mixed salt and fresh water in estuaries is called brackish water.
Which French marine explorer, scientist, and researcher is famous for his invention, the Aqua Lung?
The Aqua Lung, invented in 1942, was the first self-contained, underwater breathing apparatus (SCUBA).
Cousteau also had his own television series, The Undersea World of Jacques Cousteau, and authored many books, including The Silent World: A Story of Undersea Discovery and Adventure.
What causes the Earth's seasons?
The Earth being tilted on its axis relative to light from the sun.
The Earth's axis (mythical line through the north and south poles) tilts about 23.5 degrees from a perfect perpendicular to the sun. Therefore, when the north pole is tilted toward the sun, the northern part of the world has summer because it receives more direct sunlight.
When the north pole is tilted away from the sun, it's winter in the Northern Hemisphere (and summer in the Southern Hemisphere).
This Earth feature lies at 0º longitude and separates the Eastern and Western Hemispheres.
The prime meridian
This Earth feature lies at 0º latitude and separates the Northern and Southern Hemispheres.
The equator is approximately 25,000 miles long.
What causes the ocean tides?
Gravitational attraction between the Earth and moon
The world's oceans effectively bulge out as a result of the gravitational attraction of the moon as it rotates around the Earth. As the moon is above one part of the Earth, the ocean bulges out there toward the moon. Simultaneously, a bulge is also created on the exact oppostite side of the globe as the whole Earth is attracted toward the moon. Thus, there are two tides per day as the Earth makes a full rotation per day.
The study of landforms and how to map them is called ___.
Topographic maps are designed to show relief (contours) on the Earth's surface -- from both natural and man-made features.
What causes thunder and lightning?
Lightning is caused by the build up of electrical charges from the collision of ice and liquids in the turbulent inside of clouds during a thunderstorm.
When the electrical fields become strong enough, lighting happens. Thunder is sound caused by the lightning, which heats the air to temperatures up to 54,000 °F, and which causes a rapid explosion, contraction, and vibration of the air that we hear as thunder.
Lightning and thunder occur in quick succession, but we see the lightning before we hear thunder because the speed of light is faster than the speed of sound.
If you hear the thunder 5 seconds after seeing lighting, how far away was the lighting strike?
The sound caused by the lighting travels to your ears at about 343.6 meters / second (at 20 °C / 68 °F), which is about 768 miles per hour (the speed of sound).
For every 5 seconds you count after seeing the lightning, it is about one mile away. If you barely count to 1 or 2, run like hell. :)
What are the four steps in the water cycle?
Evaporation: Water evaporates into the atmosphere.
Condensation: Water condenses within clouds.
Precipitation: Water falls from the sky in the form of snow or rain.
Collection: Water collects on the Earth's surface.
What phenomenon occurs when a rock fault shifts and energy is released?
When earthquakes occur, seismic waves are released that shake the Earth. The amplitude of these seismic waves is measured on the Richter scale, ranging in intensity from minor (<2) to strong (9+).
What violent weather phenomenon sometimes occurs as a result of intense low pressure systems forming over warm oceans in the summer and early fall?
Hurricanes are measured using the Saffir–Simpson hurricane wind scale. The strongest hurricanes are Category 5 and achieve wind speeds over 157 mph. Tropical Storms and Tropical Depressions are lower than Category 1 on this scale, with wind speeds of 39–73 mph and 38 mph or less, respectively.
Hurrincanes slowly die after they move over cooler waters, which do not have enough heat to evaporate enough water vapor to keep fueling the hurricane.
Any type of rock or debris that falls due to gravity is referred to as a __________.
Landslides result from overly steep slopes, erosion, severe weather, earthquakes, and volcanoes.
What violent weather phenomenon can occur when air at very different temperatures and levels of humidity meets, and is characterized by extremely high winds?
In the U.S., tornadoes often form when warm, wet air traveling north from the Gulf of Mexico meets cold, dry air traveling south from Canada during spring and summer. A tornado's winds can reach speeds of over 300 mph and span miles.
What is acid rain and why is it harmful to the environment?
Acid rain is precipitation that has a higher-than-average acidity, often due to high levels of nitric and sulfuric acid.
Localized acid rain may be the result of natural processes, such as volcanic eruptions, or manmade sources such as fossil fuel emissions. It impacts the environment by raising the acidity of rivers and lakes, which can affect fauna. Acid rain can also cause accelerated erosion to buildings.
What phenomenon is defined by large waves in oceans or lakes that can cause tremendous damage?
A tsunami can result from a number of scenarios, including underwater landslides, earthquakes, or volcanic eruptions.
The deadliest tsunami occurred in 2004 in the Indian Ocean. The cause of the tsunami was an undersea earthquake measuring 9.0 on the Richter scale. Waves from the tsunami reached 50 feet, and resulted in over 150,000 dead or missing persons.