On Earth, the period of a pendulum is given by:

where L is the length of the pendulum and

is the gravitational acceleration on Earth.
Similarly, the period of the same pendulum on Mars will be

where

is the gravitational acceleration on Mars.
Therefore, if we want to see how does the period of the pendulum on Mars change compared to the one on Earth, we can do the ratio between the two of them:

Therefore, the period of the pendulum on Mars will be 1.63 times the period on Earth.
Answer:
The pacific ocean
Explanation:
because the pacific ocean is where many earthquakes and volcanic eruptions occur.