The term 'temblor' is a synonym for an earthquake, derived from the Spanish word 'temblar,' meaning to tremble. It refers to the sudden shaking of the Earth's surface caused by the release of energy in the lithosphere that creates seismic waves.

Earthquakes are the result of a sudden release of energy in the Earth's lithosphere that creates seismic waves. These tremors occur due to the movement of tectonic plates along fault lines or volcanic activity. The study of these seismic events is crucial for understanding the internal structure of the Earth and for disaster risk management in seismically active regions across the globe.

While earthquakes originate in the brittle crust, the lithosphere includes the crust and the rigid uppermost part of the mantle. Tectonic plate movements and the resulting stress accumulation often occur within this upper mantle region. The release of this energy causes seismic waves that propagate through the Earth. Note: The answer key identifies the upper mantle, which is geologically consistent with lithospheric plate dynamics.

Earthquakes with a magnitude of 3 or less on the Richter scale are often classified as micro-earthquakes. While they are recorded by sensitive seismographic instruments, they are typically too weak to be felt by humans unless they are located very close to the epicenter and the observer is in a quiet environment.

A seismograph is a scientific instrument used to detect and record seismic waves produced by earthquakes, volcanic eruptions, or other ground motions. It provides the data necessary to calculate the earthquake's magnitude and epicenter.

The Richter scale is a base-10 logarithmic scale. This means that each whole number increase on the scale represents a tenfold increase in the measured amplitude of seismic waves. For example, an earthquake of magnitude 6 is ten times more powerful in terms of wave amplitude than a magnitude 5 earthquake.