Plate Tectonics Trivia Quiz

Answer: Alfred Wegener

Wegener, a German, first published his theory back in 1912, and Du Toit and Holmes were two people who supported it. However, most people thought that his theory was ridiculous, and it met with scepticism. It wasn't until 20 or 30 years after his death (1930) that Wegener's theory was taken seriously. Francis Bacon was an English scientist, who was the first person to notice this, but he and others at the time (early 17th century) discounted the theory, as the idea was considered to be absurd.

Answer: Pangaea

Both Laurasia and Gondwanaland are the names for the continents that formed after the separation of Pangaea. Laurasia is the name for the North American, European and Asian parts, and Gondwanaland is the name for the Indian, African, South American and Antartican part. Nazca is the name of a plate that exists to the west of South America.

Answer: 1915

The theory, supported by various pieces of evidence, was met with much scepticism at the time. The theory was supported by five pieces of evidence -
jigsaw fit, where the continents can be shown to fit together, tectonic fit, where mountain ranges extend across different continents, and fossil evidence, where similar fossils are found in now widely separated places among them.

Answer: Atlantic

Although evidence was later found in the Pacific Ocean for sea floor spreading, the first evidence was found along the Mid-Atlantic ridge. Sea floor spreading involves molten magma rising to the surface and solidifying. This in itself wouldn't be enough to support the theory, but because the earth's magnetic field changes every 400,000 years or so, magnetic 'stripes' form, which are mirrored accurately on the opposite sides of the ridge.

The rocks are aligned alternately towards the north and south poles.

Answer: Silicon

Granite and aluminium are generally limited to continental plates. These are the main features of composition, along with silicon and oxygen, whereas oceanic plates are made up of mainly basalt, silicon, magnesium and oxygen. Continental plates are also a lot older than oceanic plates, they are lighter in density and they are considerably thicker.

Answer: Rift valleys

Oceanic ridges are formed when land moves apart in the ocean. Rift valleys are formed when brittle crust is fractured as sections of it move apart. This crust then drops to form rift valleys. The largest of these can be found in Africa, where the rift extends about 4,000km from Mozambique to the Red Sea.

This area is also associated with volcanic activity as the eastern part of Africa may be starting to split away from the rest of the continent.

Answer: Subduction

Examples of subduction include the Nazca plate subducting underneath the South American plate on the western side of the continent, which has caused the formation of the Andes fold mountains. If two continental plates converge, then in most cases, collisions will occur. An example of this is the Indian plate and the Asian plate, which led to the formation of the Himalayas.

Answer: Two plates moving past each other

The best example of this is the San Andreas Fault Line. The Pacific and North American plates are constantly moving past each other at different speeds. This movement causes stress between the two plates, and as sections rub past each other, the tension released can cause earthquakes.

This is why earthquakes are so common around Los Angeles and San Francisco. However, because no subduction is occuring, there are no volcanoes caused by this fault line.

Answer: Anywhere

Hot spots are unique in that they form volcanoes that aren't necessarily related to subduction or any other form of tectonic activity. A good example of hot spots is Hawaii. The Hawaiian islands were formed by hotspots in a process that is still ongoing. Kauai, the most northwesterly Hawaiian island, is the oldest island and was formed first, which is evidence that the Pacific plate is moving northwest. Loihi is the name of an underwater volcano in Hawaii, which is believed to be the next island that will be formed.

Answer: The Ring of Fire

The rest of the names are simply slightly eccentric suggestions that I made up myself. The Pacific Ring of Fire is home to about 90% of the world's earthquakes.