What was unknown to scientists during Wegener’s time?(1 point)
Responses
Mountain ranges of some continents lined up.
Mountain ranges of some continents lined up.
The coasts of some continents fit together.
The coasts of some continents fit together.
Earth’s crust is made of plates that move.
Earth’s crust is made of plates that move.
Fossils were found in many places.
Fossils were found in many places.
During Wegener's time, scientists were unaware of several important concepts:
1. The idea that mountain ranges of some continents lined up: This concept is known as continental drift or plate tectonics. It suggests that the Earth's continents were once connected, forming a supercontinent called Pangaea, which later broke apart and the pieces moved to their current positions. Scientists at the time did not have sufficient evidence or a comprehensive explanation for why the mountain ranges of certain continents appeared to match up.
2. The understanding that the coasts of some continents fit together: This concept is closely related to continental drift. Wegener proposed that the coastlines of South America and Africa seemed to fit together like puzzle pieces, indicating that they were once joined. However, at that time, scientists did not fully grasp the significance of this observation or the implications for the movement of continents.
3. The knowledge that Earth's crust is made of plates that move: Wegener's theory of continental drift was met with skepticism during his time, and it wasn't until the mid-20th century that the concept of plate tectonics emerged. Plate tectonics explains that Earth's lithosphere (the rigid outermost layer of the planet) is divided into several large plates that are constantly moving and interacting with each other. This movement is responsible for phenomena such as earthquakes, volcanic activity, and the formation of mountain ranges.
4. The realization that fossils were found in many places and provided evidence for continental drift: Wegener noted that the distribution of certain fossils appeared to coincide across the separated continents, suggesting they were once part of the same landmass. However, during his time, scientists had limited knowledge of fossil records and did not fully appreciate the significance of this evidence in supporting the theory of continental drift and the movement of continents.