Directions for teachers:

Ask students to read the online Science News “Greece’s Santorini volcano erupts more often when sea level drops,” which describes how a computer simulation revealed a hidden relationship between sea level and a volcano’s explosive history. A version of the story, “Sea level dips spur volcanic eruptions,” appears in the August 28, 2021 issue of Science News.

Directions for students:

Read the online Science News “Greece’s Santorini volcano erupts more often when sea level drops,” which describes how a computer simulation revealed a hidden relationship between sea level and a volcano’s explosive history. A version of the story, “Sea level dips spur volcanic eruptions,” appears in the August 28, 2021 issue of Science News.

1. What is Santorini and where is it located?

Santorini is a ring of Greek islands surrounding the tip of a volcano jutting out of the Aegean Sea.

2. What was the Santorini volcano like before 1600 B.C.? What happened to the volcano that year?

The volcano was above water before 1600 B.C. That year, a violent eruption caused part of the volcano to collapse, creating a lagoon.

3. A claim is an assertion of something as a fact, which may or may not be supported by evidence. What is one scientific claim made by the scientist as described by the article?

Changes in sea level after the Santorini volcano partially collapsed influenced its eruptions.

4. Claims often serve as answers to questions. What scientific question might the scientist’s claim attempt to answer?

What specific stresses can impact volcanoes located in or around large bodies of water?

5. Evidence is the scientific data that are given to support a claim. What information does the article give as evidence? Be sure to state where the evidence comes from.

A computer simulation of the volcano’s magma chamber showed that when the sea level dropped 40 meters or more below the present-day level, the crust above the chamber cracked, allowing magma to make its way to the surface. After water rises again, the cracks eventually close and eruptions stop, according to the simulation. Comparing geologic data of past sea level with the volcano’s eruption history supported the simulation’s prediction.

6. Reasoning is the explanation of why the evidence supports the claim. What reasoning is given in the article?

One statement of reasoning that loosely relates the evidence back to the scientist’s claim is that other studies have found a similar relationship between volcanoes in Iceland and glaciers. Icelandic volcanoes have shown an increase in eruptions after glaciers that were once on top of them melted, relieving the system of the ice’s weight.

7. What do the findings mean for the Santorini volcano today, according to scientists?

The Santorini volcano will likely remain relatively quiet, scientists say, because the last time sea level was 40 meters below the present-day level was thousands of years ago near the end of the last ice age and sea level is rising due to climate change. But violent eruptions are still possible — two historic major eruptions happened when sea levels were high.

8. How might the findings apply to other volcanoes?

Sea levels probably influence other volcanoes. More than half of the world’s volcanic systems are in or near oceans.