Reverse faults, particularly those along convergent plate boundaries are associated with the most powerful earthquakes, megathrust earthquakes, including almost all of those of magnitude 8 or more. Strike-slip faults, particularly continental transforms, can produce major earthquakes up to about magnitude 8.

Today, we know that the continents rest on massive slabs of rock called tectonic plates. The plates are always moving and interacting in a process called plate tectonics. The continents are still moving today. As the seafloor grows wider, the continents on opposite sides of the ridge move away from each other.

The causes of continental drift are perfectly explained by the plate tectonic theory. The earth’s outer shell is composed of plates that move a little bit every year. Heat coming from the interior of the earth triggers this movement to occur through convection currents inside the mantle.

The World’s 10 Most Earthquake Prone Countries

Japan

Tsunamis are caused by violent seafloor movement associated with earthquakes, landslides, lava entering the sea, seamount collapse, or meteorite impact.

California has more earthquakes that cause damage than any other state. Alaska and California have the most earthquakes (not human-induced).

San Francisco May Be a Good City, but Not Very Earthquake-Proof. If you are wondering — what part of California gets the most earthquakes? — Frisco is your answer.

Plate tectonic theory explains why continents continue to move. The planet’s outer shell consists of plates that move a few centimeters a year. Heat from the Earth’s interior causes this motion to happen via convection currents in the mantle.

Several of the tectonic plates are currently moving north, including both Africa and Australia. This drift is believed to be driven by anomalies left by Pangea, deep in the Earth’s interior, in the part called the mantle.

In the early part of the 20th century, scientists began to put together evidence that the continents could move around on Earth’s surface. The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones.

Holmes proposed that the continents, which “floated” on the Earth’s mantle, moved with the convection flow of the magma (hot semifluid below the Earth’s crust). The mechanism of continental drift is like the flow of branches floating in the moving waters of rivers, as shown in Figure 3-11.4.

You can’t swim under islands. Islands can be created in multiple ways, but they are all connected to the seabed.

But floating islands do indeed exist on six of the seven continents and sometimes in the oceans between them. These islands are kept buoyant by the light spongy tissues of certain aquatic plants, by gases released into their soil by decomposing vegetation, or by both these forces.

Bananas float in water because they are less dense than water. Also, fruits like watermelons, apples and oranges float in water because they have so many air pockets in them. Yes, banana can indeed float in the water – depending on the density.

Pi, Richard Parker, and the man on the lifeboat are blind because of poor nutrition. The scene is a metaphor for Pi’s whole voyage. Their blindness represents how all of them are lost on the ocean without knowing where they’re going. At first, Pi thinks Richard Parker is talking to him, showing how near death he is.

Watermelons are nearly neutrally buoyant, they will sink in the water and slowly float to the surface. This feature makes them great for passing under the water and excellent for playing a football-like or rugby-like game in the water.

Apples can float because 25% of their volume is air. If an item is more dense than water it will sink, it is less dense it will float. Apples are less dense than water, so they float!

Key statistics

Pumpkins and apples float in the water because they are less dense than the water – meaning they are buoyant.

In the salt water, the pencil sinks below the water surface. In the salt water, more of the pencil is below the water than before. In the salt water, more of the pencil is above the water than before. In the salt water, the same amount of the pencil is above the water as in the fresh water.

An object floats when the weight force on the object is balanced by the upward push of the water on the object. If the weight force down is larger than the upward push of the water on the object then the object will sink. If the reverse is true then the object will rise – rising is the opposite of sinking.

What do the pencil and Popsicle stick have in common? They are both made out of wood. A characteristic property of wood is that it floats.

A metal spoon, a plastic spoon, a metal paper clip, a coin, a ping-pong ball, an apple, and an orange. The metal items will sink and everything else will float. The apple, ping pong ball, orange, and plastic spoon will float.

Objects are made up of very tiny molecules. Objects with tightly packed molecules are more dense than those where the molecules are spread out. Density plays a part in why some things float and some sink. Objects that are more dense than water sink and those less dense float.

We all know that gasoline, fuel oil, and diesel fuel float on water because each mixture has a lower specific gravity than does water.

Styrofoam is very light weight, so the density is very low – lower than water, so it floats.

If the molecules inside an object are very close together, the item is solid, or dense. A cork, piece of wood, or Styrofoam floated because those materials have less density than water. All the objects that were less dense than water floated in the water! Objects that were more dense than the water sank.