1. What was wrong or why do you think people rejected Wegner's idea of continental drift?
2. Explain why some partly molten lava rises toward Earth's surface.
what about the 2nd question?
1. People initially rejected Wegener's idea of continental drift for several reasons, primarily due to a lack of evidence and the absence of a plausible mechanism explaining how the continents moved. Here's a step-by-step explanation of why people were skeptical:
a. Lack of evidence: Initially, Wegener's idea lacked concrete evidence to back it up. He primarily relied on observational similarities between the coastlines of continents, which were once part of the supercontinent Pangaea. However, at that time, the geological community did not have sufficient data to support his claims.
b. No mechanism: One significant factor that led to rejection was the absence of a convincing mechanism to explain how continents could move. Wegener suggested that the continents plowed through the oceanic crust, implying that trenches should exist at the leading edge of continents. However, no such trenches were observed, further diminishing the credibility of his proposal.
c. Geophysical objections: Prominent geophysicists of the time criticized Wegener's theory. They argued that the Earth's mantle was solid and rigid, making it unlikely for continents to plow through it. They believed in a concept called "fixism," which suggested that the positions of continents were fixed since their formation.
d. Lack of scientific consensus: Many scientists and geologists were hesitant to accept a new theory without strong evidence. This hesitation was partly due to prior experiences with other radical scientific theories that had proven to be incorrect. As a result, Wegener's theory did not gain wide acceptance during his lifetime.
However, over time, accumulating evidence from different fields, including paleontology, geology, and geophysics, supported the idea of continental drift. This eventually led to the development of the modern theory of plate tectonics, which incorporated Wegener's original proposal.
2. When it comes to partially molten lava rising toward Earth's surface, the phenomenon can be explained using a combination of factors related to density, pressure, and buoyancy:
a. Density differences: Partially molten lava, or magma, is generally less dense than the surrounding solid rock found in Earth's mantle. Due to this density difference, the lighter magma tends to rise toward the surface.
b. Pressure release: As the magma rises, it encounters reduced pressure. This pressure reduction occurs when the overlying rock is less dense than the magma. The decrease in pressure allows the magma to expand, leading to further upward movement.
c. Buoyancy: The principle of buoyancy also plays a role. Magma is buoyant in nature, similar to how objects float in water. The magma's buoyant force, which is a result of the density difference, pushes it upward.
d. Magma chambers: Magma gathers in reservoirs known as magma chambers, which can be found beneath the Earth's surface. These chambers act as localized sources or storage areas for molten rock. The pressure build-up and continuous supply of magma from the Earth's mantle contribute to the rising behavior.
The combination of these factors allows some partially molten lava to ascend towards the Earth's surface, potentially leading to volcanic activity or the formation of volcanic features such as volcanoes and lava flows. It's important to note that the specifics of magma behavior can vary depending on the composition, temperature, and other geological factors involved.