Jonathan Amos, BBC News

媒體英語會帶大家一起學習 BBC 撰稿人在報道世界大事時常用到的單詞和短語。

Background: 夏威夷的基拉韋厄火山每年都吸引著兩百萬觀光者前去觀賞并拍照其壯觀的巖漿湖。不過科學家們發現基拉韋厄火山的歷史上充滿了動蕩噴發紀錄。如果它再次爆發老脾氣，那么這對夏威夷的經濟將有直接影響。

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.