文章中將出現的生詞：
collapse：vi倒塌，瓦解，暴跌；vt使倒塌，使崩潰，使萎陷；n倒塌，失敗，衰竭
trigger：vt出發，引發；vi鬆開扳柄；n觸發器，扳機
assessment：n評估，估價
satellite：n衛星
catastrophe：n災禍
infrasound：n次聲
prior：adj在先的；adv在前
flank：n側面；vt守側面，攻側面，位於……的側面；vi側面相接；adv在左右兩邊
strait：n海峽，困境；adj狹窄的，苦惱的
tragedy：n悲劇
seismic：adj地震的，因地震引起的
interpretation：n解釋，表演
robust：adj強健的，粗野的
cascade：n層疊，小瀑布，噴流；vi像瀑布般衝下；vt使像瀑布般衝下
intense：adj強烈的，緊張的，熱情的，非常的
thermal：adj熱的，熱量的
initiate：vt開始；n開始，新加入者；adj新加入者
vulnerable：adj易受傷的，脆弱的
precursor：n先驅者，前兆
deformation：n變形，殘廢
algorithm：n運算法則
anomalous：adj不規則的
densification：n增濃作用
Anak Krakatau volcano collapse: 'Warning signs were there'
Anak Krakatau火山坍塌：「警告標誌在那裡」
By Jonathan Amos
BBC Science Correspondent英國廣播公司科學記者
Anak Krakatau, the Indonesian island volcano that collapsed last December triggering a huge tsunami, did produce clear warning signals before the event. 去年12月倒塌並引發巨大海嘯的印度尼西亞島嶼火山阿納克·克拉卡託（Anak Krakatau）在事件發生之前確實發出了清晰的警告信號。
That's the assessment of a German-led team which has reviewed all the data. 那是一個由德國領導的小組進行的評估，該小組審查了所有數據。
The scientists say satellites in the months leading up to the catastrophe had observed increased temperatures and ground movement on the volcano. 科學家們說，在災難發生前的幾個月中，衛星觀測到了火山上的溫度升高和地面運動。
Earthquake and infrasound activity was also detected two minutes prior to the collapse of Anak's southwestern flank. 在Anak西南側坍塌前兩分鐘，也發現了地震和次聲活動。
When this mass slid into the sea, it sent a wall of water, up to 4m high, around the Sunda Strait. 當這些重物滑入海中時，它在Sunda海峽周圍送出了高達4m高的水牆。
More than 400 people died in the 22 December tragedy; a further 7,000 were injured and nearly 47,000 were displaced from their homes. 在12月22日的悲劇中，有400多人喪生；另有7,000人受傷，近47,000人流離失所。
Thomas Walter, from the German Research Centre for Geosciences GFZ in Potsdam, said any of the different signals viewed individually could not have been used to predict what happened at the island volcano, but taken together they might well have raised a red flag.
來自波茨坦的德國地球科學研究中心GFZ的託馬斯·沃爾特（Thomas Walter）說，單獨觀察的任何不同信號都不能用來預測島上火山的情況，但加在一起，它們很可能會發出危險信號。
"If you took any of the sensors on their own, the interpretation would not be robust, but by pulling together all of the different sensors we can draw a picture of the cascade that was going on," Dr Walter told BBC News.
沃爾特博士對英國廣播公司新聞說：「如果您單獨使用任何一個傳感器，其解釋將不會很可靠，但是通過將所有不同的傳感器放在一起，我們可以繪製出正在發生的級聯的圖像。」
The team noted that the volcano was experiencing its greatest eruptive phase in 20 years in 2018; that its southwestern flank had begun edging seaward from January onwards; that there was an intense phase of thermal activity initiated on the 340m-high mountain in June, and that there had been an increase in the island's surface area in the months leading up to the collapse.
研究小組指出，火山正在經歷2018年20年來最大的噴發階段。從一月份開始，它的西南側面已經開始向海邊緣移動；在6月，在340m高的山峰上開始了激烈的熱活動階段，在倒塌之前的幾個月中，該島的表面積有所增加。
There was also significant seismic behaviour just before the collapse. Perhaps an earthquake, maybe an explosion; it's not clear. 倒塌之前也有明顯的地震行為。也許是地震，也許是爆炸；還不清楚。
But what was interesting, explained Dr Walter, was that this seismic signal did not go down to zero. And when it picked again, it displayed a low frequency that is characteristic of landslide behaviour. 但是，瓦爾特博士解釋說，有趣的是，該地震信號並未下降到零。當再次發信號時，它顯示出（山體）滑坡行為特徵的低頻。
A couple of minutes further on in time, the frequency changes again, which the team interprets as a barrage of volcanic explosions - as "the cork comes off the top of the bottle".再過幾分鐘，頻率再次改變，該團隊將其解釋為一連串火山爆發-因為「軟木塞從瓶頂掉下來」。
As to how the lessons learned at Anak Krakatau should be used at other vulnerable volcanoes, Dr Walter said the kind of flank movement observed on the Indonesian island could be regarded as a potential long-term precursor.
至於在Anak Krakatau中學到的教訓應如何用於其他脆弱的火山，沃爾特博士說，在印度尼西亞小島上觀察到的這種側翼運動可被視為潛在的長期先兆。
Radar satellites will detect this deformation and a number of groups around the world are even developing automated systemsin which algorithms hunt through the spacecraft data for evidence of anomalous activity.雷達衛星將檢測到這種變形，世界各地的許多小組甚至都在開發自動化系統，在該系統中，算法會搜尋太空飛行器數據以尋找異常活動的證據。
Last December, seismic and infrasound networks caught the moment of collapse. "But we have many volcanoes around the world where there are no such stations nearby," Dr Walter said. "We should look at those volcanoes where there is a risk of sector collapse and invest in a densification of instruments."
去年12月，地震和次聲網絡陷入了崩潰的時刻。沃爾特博士說：「但是我們在世界各地有許多火山，附近沒有這些火山站。」 「我們應該研究那些存在有部分崩潰風險的火山，並投資於增加設備分布密度。」
The GFZ volcanologist's team has published its findings in the journal Nature Communications. GFZ火山學家的團隊已在《自然通訊》雜誌上發表了其發現。
英文原文來自BBC，作者Jonathan Amos，中文翻譯和生詞整理由「英文科學文章閱讀」製作。
今天和大家分享的是一篇與自然災害預警有關的文章。我國近年來發生過幾次嚴重的自然災害，而大多數自然災害發生的很突然。幾百年前，我們就可以精確預測宇宙中哈雷彗星的到來，而我們至今不能完全預測地球上自然災害的發生，這不得不說是一件悲哀的事情。實現完全預測自然災害，我們依然有很長的路要走。
看完這篇文章，大家對自然災害的預測有什麼想法呢？