Krakatau: When an Eruption Moved the Sea
On August 27, 1883, enormous waves swept toward the shores of Java and Sumatra. The sea rushed over coastal communities, destroying buildings and carrying away people and boats. The source of the disaster was not a storm. It was a volcano called Krakatau, erupting in the water between the two islands in what is now Indonesia.
An island begins to erupt
Krakatau stood in the Sunda Strait, the waterway separating Java and Sumatra. In May 1883, after a long quiet period, the volcano began erupting. It sent ash and steam into the air, and ships passing through the strait reported activity. Over the following months, eruptions continued and grew stronger.
An eruption begins underground, where melted rock called magma collects. Magma contains gases. As it rises, pressure around it decreases, allowing gases to expand. If gas-rich magma breaks apart violently, an explosion can send ash and pieces of rock high into the air.
By August 26, Krakatau’s eruption had become much more powerful. Huge clouds of volcanic material rose above the island. Ash darkened the sky, while hot mixtures of gas, ash, and rock rushed outward from the volcano.
The sea is pushed aside
- coastal:
- Located near the edge of the sea.
- pressure:
- A force that pushes on something.
- disturbance:
- A change that interrupts a calm or normal state.
- contributed:
- Helped cause or bring about something.
- surged:
- Moved forward suddenly and powerfully.
- instruments:
- Tools used to measure or record information.
- landscape:
- The land and its natural features in an area.
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Preview questions from this passageShowHide
- 1How did Krakatau’s eruption show that a volcanic disaster can reach coastal communities across the sea?
- 2Why can rising magma cause an explosion?
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About this explanatory article passage for Upper Elementary
“Krakatau: When an Eruption Moved the Sea” is a explanatory article reading passage about Volcanic eruptions and tsunamis, written for Upper Elementary. It takes about 3 minutes to read (484 words) and comes with an interactive quiz and a printable worksheet with comprehension questions and an answer key.