What was unknown to scientists during Wegener's time? (1 point)
O Fossils were found in many places
O Earth's crust is made of plates that move
• Mountain ranges of some continents lined up
© The coasts of some continents fit together.
• Earth's crust is made of plates that move.
• Mountain ranges of some continents lined up.
• The coasts of some continents fit together.
The correct answer is: O Earth's crust is made of plates that move
During Wegener's time, the idea that Earth's crust is made of plates that move was unknown to scientists. This concept, known as plate tectonics, was not widely accepted until the mid-20th century. Wegener, a German scientist, proposed the theory of continental drift in the early 20th century. He suggested that the continents were once joined together in a single supercontinent called Pangaea and gradually moved apart to their current positions. However, Wegener's theory lacked a mechanism to explain how the continents moved. The concept of plate tectonics, which explains that the Earth's lithosphere is divided into several rigid plates that glide over the semi-fluid asthenosphere beneath them, wasn't fully developed until the 1960s. Plate tectonics provided the mechanism necessary to explain continental drift and many other geological phenomena, such as the creation of mountain ranges, earthquakes, and the formation of ocean basins.
During Wegener's time, what was unknown to scientists was the fact that Earth's crust is made of plates that move. This concept, known as plate tectonics, was not yet understood during that time. However, scientists did observe other pieces of evidence such as fossils found in different places, mountain ranges lining up, and the coasts of certain continents fitting together, which eventually contributed to the development of the theory of plate tectonics.
What was unknown to scientists during Wegener's time? (1 point)
O Fossils were found in many places
O Earth's crust is made of plates that move
• Mountain ranges of some continents lined up
© The coasts of some continents fit together.
Choose one
The correct answer is: O Earth's crust is made of plates that move.
Which continents have coastlines and mountain ranges that match up? (1 point)
O Africa and North America
O North America and South America
O Africa and South America
O Asia and Antarctica
The correct answer is: O Africa and South America.
What did scientists observe in the ocean floor which indicates that the Pacific Ocean is becoming smaller? (1 point)
• plates floating on the mantle
O subduction
• continental drift
• spreading
The correct answer is: O subduction.
Scientists observed subduction in the ocean floor as evidence that the Pacific Ocean is becoming smaller. Subduction is the process by which one tectonic plate is forced beneath another plate, typically in a subduction zone. In the case of the Pacific Ocean, the Pacific Plate is being subducted beneath other plates, leading to the shrinkage of the ocean.
What is the name of a supercontinent that was once made up of all of Earth's current continents!
(1 point)
• Gondwana
O Laurasia
O Pangaea
• Eurasia