1:An earthquake has a high magnitude but a low intensity. Which statement best explains this?
a: Magnitude measures the energy released by the earthquake, while intensity measures its duration.
b: Magnitude measures the energy released by the earthquake, while intensity measures the amount of damage.
c: Magnitude measures the duration of the earthquake, while intensity measures the energy released by the earthquake.
d: Magnitude measures the duration of the earthquake, while intensity measures the amount of damage.
b: Magnitude measures the energy released by the earthquake, while intensity measures the amount of damage.
b: Magnitude measures the energy released by the earthquake, while intensity measures the amount of damage.
The correct answer is b: Magnitude measures the energy released by the earthquake, while intensity measures the amount of damage.
To understand why this statement is true, let's first clarify the definitions of magnitude and intensity when it comes to earthquakes.
Magnitude is a measure of the total energy released by an earthquake at its source. It is determined using seismic records and is represented by a single numerical value on a logarithmic scale, such as the Richter scale or the moment magnitude scale (Mw). The magnitude does not change with distance from the epicenter, and it reflects the potential strength of the earthquake.
On the other hand, intensity measures the effects of an earthquake at various locations, taking into account the distance from the epicenter and the geology of the area. Intensity is determined through observations and reports from people who felt the shaking. It is typically described using the Modified Mercalli Intensity (MMI) scale, which ranges from I (not felt) to XII (total destruction). Intensity provides information about the level of shaking and damage experienced at different locations.
So, when the statement says that an earthquake has a high magnitude but a low intensity, it means that the earthquake released a substantial amount of energy at its source (high magnitude), but it did not cause significant damage or shaking at the places where people felt it (low intensity).