GEOLOGY

Detailed explanation-1: -There are about 1, 500 potentially active volcanoes worldwide and about 50 eruptions occur each year.

Detailed explanation-2: -Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots.”

Detailed explanation-3: -Geological, historical and dating records for volcanic eruptions on land become less complete further back in time. Since 1500 AD, there are 596 volcanoes that are known to have erupted. The record since 1950 is believed to be almost complete with 2, 208 eruptions recorded from 347 volcanoes.

Detailed explanation-4: -It is estimated that about 50 to 60 volcanoes erupt every year on Earth, so there would be about 500 to 600 eruptions over 100 years. Most of these eruptions are not noticed by anyone other than scientists who monitor the volcanoes for activity.

Detailed explanation-5: -There are about 1, 350 potentially active volcanoes worldwide, aside from the continuous belts of volcanoes on the ocean floor at spreading centers like the Mid-Atlantic Ridge. About 500 of those 1, 350 volcanoes have erupted in historical time.