Plate Tectonics & Boundaries
Most volcanoes in the "Ring of Fire" form where these structures meet each other.
What are tectonic plates?
This German scientist proposed the hypothesis of continental drift in 1912.
Who was Alfred Wegener?
Providence Canyon in Georgia was formed primarily by the erosional power of this natural agent carrying sediment away over time.
What is running water (or surface water runoff)?
According to the Law of Superposition, in an undisturbed cross-section of sedimentary rock, the oldest layer is found here.
What is at the bottom?
The central region of the U.S. that experiences an average of over 1,200 tornadoes annually is commonly known by this nickname.
What is Tornado Alley?
At a mid-ocean ridge like the Mid-Atlantic Ridge, this type of plate movement occurs as two plates move away from each other.
What is a divergent boundary?
The observation that these two continents look like matching puzzle pieces was early evidence for continental drift.
What are South America and Africa?
In a stream table experiment, increasing the incline angle causes water to move faster, which increases this type of energy in moving water.
What is kinetic energy?
According to the Law of Superposition, the youngest layer in an undisturbed rock sequence is found here.
What is at the top?
Looking at historical landslide risk maps, areas with steeper slopes and a history of previous landslides present this level of risk for future landslides.
What is high risk?
The Andes Mountains were formed by this type of plate movement where the Nazca Plate and South American Plate collide.
What is a convergent boundary?
Finding identical rock layers and fossils of this ancient fossil fern across South America, Africa, India, Australia, and Antarctica supports continental drift.
What is Glossopteris?
As stream velocity increases, a stream channel tends to widen because the moving water picks up and transports more of this material.
What is sediment (or sand)?
An igneous rock intrusion that cuts through several existing rock layers is always this compared to the layers it cuts across.
What is younger?
In 2011 U.S. natural disaster data, this hazard caused the highest number of direct occurrences by far, exceeding 1.3 million events.
What are wildfires?
The Mid-Atlantic Ridge forms underwater mountains primarily because plates shift and new sea floor is created by magma rising at this type of boundary.
What is a divergent boundary?
Finding fossilized remains of ancient tropical plants or coal deposits in frozen regions like Antarctica indicates that Antarctica was once located here.
What is closer to the equator (or a warmer/tropical climate)?
Marine organism fossils in the layers of Providence Canyon suggest that this area was once covered by a shallow ocean or shoreline that experienced alternating sea levels depositing these.
What are sediment layers (or sedimentary rock)?
Geologists can match rock layers across huge distances by looking for matching rock types and these preserved ancient remains.
What are index fossils (or fossils)?
To evaluate a state's risk and prepare emergency response budgets for natural disasters, emergency management officials look at historical frequency data and this financial metric.
What is damage cost (in dollars)?
High in the Andes Mountains, marine fossils were found because this process pushed ancient ocean floors upward.
What is continental-oceanic plate collision (or subduction/tectonic uplift)?
Sea life on both sides of Latin America began to evolve differently less than 3 million years ago because this geographical change separated the Pacific and Atlantic Oceans.
What is the formation/closing of the Isthmus of Panama (or plates moving together to form a land bridge)?
The process of sediment settling out of water or wind and building up in layers over millions of years is known as this.
What is deposition?
If layer L sits below layer K, layer J, and layer G, layer L is the oldest because of this principle of geology.
What is the Law of Superposition?
Even though tornadoes occur much less frequently than wildfires in the U.S., they often result in higher financial cost than wildfires because they hit these areas.
What are populated areas / developed infrastructure (cities and towns)?