What evidence did Alfred Wegener have to support his theory?
fossil evidence
What is the evidence for Wegener’s theory of continental drift quizlet?
How did fossils provide evidence of continental drift? Wegener also found evidence for continental drift from fossils (Figure below). The same type of plant and animal fossils are found on continents that are now widely separated. These organisms would not have been able to travel across the oceans.
What is the theory of the continental drift?
Continental drift was a theory that explained how continents shift position on Earth’s surface. Set forth in 1912 by Alfred Wegener, a geophysicist and meteorologist, continental drift also explained why look-alike animal and plant fossils, and similar rock formations, are found on different continents.
Why was Wegener’s theory of continental drift almost completely discarded quizlet?
Why was Wegener’s theory of continental drift almost completely discarded? It didn’t have a mechanism for how drift occurred. What do cinders, ash and lava all have in common? They are all different forms that magma takes after volcanic eruption.
Which statement is true according to the theory of plate tectonics?
Which statement is TRUE according to plate tectonic theory? Plates of rigid lithosphere lie on top of the weak asthenosphere. Seafloor spreading occurs at this type of plate boundary. According to plate tectonic theory, convergence between two plates of ocean lithosphere created these volcanoes.
Why do some life activities strengthen the substrate while others weaken it?
Why do some life activities strengthen the substrate while others weaken it? a. Burrowing creatures distribute stronger soil around, while plants digest and weaken soil. Some organisms secrete a binding agent in the soil, while plants digest and weaken soil.
Why do beaches become sediment starved after dams are installed on rivers?
Why do beaches become sediment-starved after dams are installed on rivers? Dams trap water, thus reducing the volume of water that enters the ocean and erodes away the coast to produce sediment. Rivers supply sediment to beaches; dams trap river sediment, and thus that sediment cannot make it to the beaches.
Why do scientists believe there was once liquid water on Mars quizlet?
It is highly unlikely that liquid water exists today on the surface of Mars, due to the cold temperatures and low atmospheric pressure. Liquid water may exist temporarily, but freezes or evaporates quickly. Mars must have had a thicker atmosphere and a higher temperature in the past.
Why do meandering rivers meander move across their floodplain?
Why do meandering rivers meander (move) across their floodplain? They are curved, which causes erosion on one side of the curve and deposition on the other side of the curve, thus moving the river in the direction of erosion.
Is a 100-year flood more destructive than a 50 year flood?
Many mistakenly believe that it is a flood that occurs every 100 years. Floods are classified according to their frequency and depth. For instance, there are 10-year, 25-year, 50-year, 100-year, and 500- year floods. A 100-year flood, although less frequent than a 10-year flood, is deeper—and far more destructive.
What are two components of a river’s flow?
“Flow” refers to the water running in a river or stream. There are two important aspects to a river’s natural flow. First, there is the amount of water that flows in the river. Some rivers get enough water from their headwaters, tributaries, and rain to flow all year round.
Where does the most erosion occur on a meandering river?
Due to the slope of the channel, erosion is more effective on the downstream side of a meander. Therefore, in addition to growing laterally, the bends also gradually migrate down the valley.
What feature is created when a meander is cut off from the main river?
Upstream a large bend becomes a horseshoe and is eventually cut-off to become an oxbow lake. Downstream the river is eroding its outer bank and depositing on its inner bank to create a new meander.
Why do point bars form?
A low, curved ridge of sand and gravel along the inner bank of a meandering stream. Point bars form through the slow accumulation of sediment deposited by the stream when its velocity drops along the inner bank.
Where in a meandering streambed is water moving the fastest?
Meanders. Irregularities in the bed of a stream or river can cause the speed of water flow to be different at the two banks of the river. Where stream velocity is fastest, the water erodes the bank.
What is the fastest water can flow?
Streams. If a stream is flowing along straight, the strongest, fastest flow will be in the center of the stream well above the bottom of the bed or channel but below the surface.
How many seconds does it take for a barrel to reach 100m?
A. How many seconds did it take for the barrel to go 100 meters? B. To find the barrel’s speed, use a calculator to divide the distance traveled (100 m) by the time it took the barrel to float 100 m (91 seconds).
What are the four changes that a stream undergoes before it reaches the ocean?
1 – The flow of the river may change as water is fed out into tributaries. 2- As a river flows it may etch out the river bed and create a gulley as it moves sediment and debris. 3- Depending on the speed of a stream it can form into a meandering river with twists and turns.
What does a blocked off meander eventually become?
The blocked-off meander becomes an oxbow lake, which eventually dries up.