Question

9.) explain what the richter scale is and how it works.

10.) what are the different types of volcanoes and explain the difference between them?

11.) explain how geologists find the epicenter of an earthquake.

12.) explain what an earthquake is.

Explanation:

Question 9:

The Richter Scale is a logarithmic scale developed by Charles Richter to measure the magnitude (size) of earthquakes. It works by using the amplitude of seismic waves recorded by seismographs. Each whole number increase on the scale represents a ten - fold increase in measured amplitude and approximately 31.6 times more energy release. For example, a magnitude 5 earthquake releases about 31.6 times more energy than a magnitude 4 earthquake.

There are three main types of volcanoes:

1. Shield Volcanoes: They have broad, gently sloping sides. Formed by the eruption of low - viscosity (runny) basaltic lava. Example: Mauna Loa in Hawaii.
2. Cinder Cone Volcanoes: They are relatively small, with steep sides. Formed from the ejection of volcanic cinders (small, fragmented rocks) during explosive eruptions. Example: Paricutin in Mexico.
3. Composite (Stratovolcanoes): They have steep sides and are made of alternating layers of lava, ash, and other volcanic materials. Formed by explosive eruptions followed by lava flows. Example: Mount Fuji in Japan. The differences lie in their shape, the type of magma/lava (viscosity, composition), and the nature of eruptions (explosive vs. effusive).

Geologists use the triangulation method. First, they need at least three seismograph stations. Each station records the time difference between the arrival of P - waves (primary, faster) and S - waves (secondary, slower). Using this time difference, they can calculate the distance from the station to the epicenter (using the known speed difference between P and S waves). Then, they draw circles (with radius equal to the calculated distance) around each station on a map. The point where the three circles intersect is the epicenter of the earthquake.

Answer:

The Richter Scale is a logarithmic scale to measure earthquake magnitude. It uses seismograph - recorded seismic wave amplitudes; each whole - number increase means 10×amplitude and ~31.6×energy increase.

Question 10: