An earth tremor is another term for an earthquake, although it is most commonly used to describe earthquakes of low intensity. Earthquakes are measured with tools called seismographs, and their intensity is rated on a logarithmic scale, called the Richter scale. The Richter scale is not useful for earthquakes that rank higher than a level 8 earthquake.Know More
Earthquakes occur when the earth’s tectonic plates move and contact other plates. Sometimes the plates rub against each other laterally, while other times one plate moves underneath another. When this happens, it is called a subduction zone or a subduction-caused earthquake. In some particularly violent earthquakes, two plates collide into each other. This type of collision may even cause mountains to form, which happened millions of years ago when the Indian subcontinent crashed into Asia, producing the Himalayas.
Earthquakes are rather common, though few are strong enough to cause much damage. People may not even feel very weak earthquakes. The center of the disturbance is called the earthquake’s epicenter, and epicenters usually occur along major fault lines, where two plates contact each other. Many large and active fault lines occur around the margin of the Pacific Ocean, which has given the region the name “ring of fire” for all of the earthquakes and volcanoes in the region.Learn more about Earth Science
The term "eustatic" refers to the global sea level. This is opposed to the isostatic sea level, which is a local measurement that is often a result of tides. Eustatic sea level changes are global, and they are often the result of major upheavals to the climate or ocean basin.Full Answer >
According to Universe Today, the duration of a day on Earth is the time it takes for the planet to complete a rotation around its axis. The Earth’s rotation takes 23 hours, 56 minutes and 4.1 seconds.Full Answer >
While no one knows for certain how the Earth formed, scientists theorize that it formed over 4 million years ago after the sun went through its initial formation, gravity began to draw heavy particles together into a planet and solar winds blew away lighter gases. These heavy particles became the core of the planet. As the mass continued to grow, heavier particles sank to the center, according to Space.com.Full Answer >
The shape of the Earth is classified as an ellipsoid or an oblate spheroid. The Earth is not considered a true sphere because it has a larger circumference and diameter at the equator. The poles of the Earth are squished, which creates a slight bulge around the equator.Full Answer >