Jonathan Amos, BBC News

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Background: 夏威夷的基拉韦厄火山每年都吸引着两百万观光者前去观赏并拍照其壮观的岩浆湖。不过科学家们发现基拉韦厄火山的历史上充满了动荡喷发纪录。如果它再次爆发老脾气，那么这对夏威夷的经济将有直接影响。

There's no doubting Kilauea's beauty. Its frequent lava flows running down to the ocean's edge are a big attraction.

But scientists say their latest research indicates that explosive eruptions of ash and rock have been far more common in the past than the gentle, photogenic outflows seen today.

By studying the charred remains of plants caught up in historic blasts, they've established that Kilauea's more violent mode has dominated the last 2,500 years.

A classic example was 1790, when the volcano hurled rock and ash at island inhabitants, killing many hundreds of people. The event remains the most lethal known eruption in America.

Scientists say it's not possible to predict if this violent behaviour will return but should it come back, large parts of Hawaii Volcanoes National Park would be off-limits for a long time.

Scientists say there should be ample warning of a change in behaviour so it's not something local people should worry about just now.