原文網址：https://news.st-andrews.ac.uk/archive/st-andrews-researchers-solve-200-year-volcanic-mystery/
最近聖安德魯斯大學的研究人員終於解開了困惑科學家將近200年，關於一場大型火山爆發究竟發生在哪的謎題。
該次神秘的爆發發生在Zavaritskii火山(位於千島群島的新知島)。爆發炸出了一座三公里寬的火山臼，露出下方由紅色、黑色與白色的岩石堆疊而成的壯麗岩層，其形成於過去的噴發事件。圖片來源：Oleg Dirksen
1831年，一場大型火山爆發噴出了大量含硫氣體到大氣當中，反射部分陽光而讓全球氣溫下降大約1°C。這段天寒地凍的時期在世界各地都有明確的記錄，其造成大範圍的農作物歉收與嚴重的饑荒。
就連作曲家費利克斯•孟德爾頌也在他1831年夏季行經阿爾卑斯山的旅程中，寫到此時的惡劣天氣：「天氣糟糕透頂，從早到晚都在不停地下雨，冷到像在冬天一樣，附近的山頭甚至已經有一層厚厚的積雪……」
1831年的火山爆發是地球「神秘的火山爆發事件」中時間最近的一樁。雖然科學家知道這是場造成氣候變遷與社會動盪的重大事件，但是在此篇研究之前，造成該爆發的火山身分長久以來都不甚清楚而有相當激烈的討論。
聖安德魯斯大學地球與環境科學院的Will
Hutchison博士是此篇新研究的主持人。文章於12月30日星期一發表在期刊《美國國家科學院院刊》(Proceedings of the National Academy of
Sciences)，內容揭示了團隊如何分析冰芯對於1831年事件的紀錄，並且找到「完美符合的指紋」來指認火山灰沉積物的過程。
「最近幾年我們才發展出從極區冰芯挑出微小的火山灰碎片，並對它們進行詳細化學分析的方法。這些碎片極為細小，大約只有頭髮直徑的十分之一，」Hutchison博士解釋。
Hutchison博士和團隊成功定出冰芯裡火山灰的精確年代，並且經由比對得出來源為新知島(Simushir)的Zavaritskii火山，其為千島群島當中一座偏遠且無人居住的島嶼。千島群島是俄羅斯與日本之間的爭議性領土，目前在俄羅斯的控制之下被用來當作戰略性軍事前哨站。蘇聯在冷戰期間將新知島作為核子潛艇的秘密基地，將船艦停泊於一座遭海水淹沒的火山口內部(不禁讓人聯想到007電影的情節)。
「我們以非常高的時間解析度來分析冰塊的化學成分，使得我們可以精確定出噴發的時間為1831的春夏之際，並且證實其規模極為猛烈。接著我們挑出微小的火山灰碎片來進行比對，這項工作花了很長一段時間，並在日本與俄羅斯的同儕大力協助下才能完成，他們寄給我們數十年前從那些偏遠的火山所採集到的樣品。」
「我們在實驗室將來自Zavaritskii與冰芯的火山灰樣品一起分析的那個時刻，真的是會讓我們想喊出『eureka！』(我發現了！)。我幾乎不敢相信分析會得出一模一樣的數值。之後我花了許多時間深入探討千島群島火山爆發的年代與規模紀錄，才能完全說服自己比對的結果是真的。」
研究成果顯現出千島群島這個火山活動極為旺盛的地區，目前為止對它們的研究卻相當貧乏。
1831年的火山爆發發生在非常偏遠的地方，但是它對全世界氣候產生的衝擊卻相當顯著，並且對人類族群造成嚴重的後果。找出這些神秘噴發事件的來源非常重要，因為這可以讓科學家繪製出地球上極有可能影響氣候的火山爆發事件，可能會在哪些地區發生並加以監測。
Hutchison博士補充：「像這樣的火山還有很多，顯示出要預測下一次大規模噴發的發生地點與時間，是件相當困難的事。」
「身為科學家與社會的一分子，我們必須思考當下一次大型火山爆發，像是1831年的事件發生的時候，要如何協調國際社會來做出應對。」
Researchers solve
200-year-old volcanic mystery
The mystery location of a giant volcanic
eruption that has puzzled scientists for almost 200 years has finally been
solved, thanks to researchers from the University of St Andrews.
In 1831, a massive volcanic eruption spewed
sulphurous gases into the atmosphere, reflecting sunlight and causing a global
cooling of approximately 1°C. This cold weather, well-documented worldwide, led
to widespread crop failures and devastating famines.
The composer Felix Mendelssohn even wrote about the
catastrophic weather during his summer journey through the Alps in 1831:
“Desolate weather, it has rained again all night and all morning, it is as cold
as in winter, there is already deep snow on the nearest hills…”
The eruption in 1831 is Earth’s most recent “mystery
eruption.” While scientists knew it was a major event that caused climatic
change and societal upheaval, the identity of the volcano responsible remained
unknown and fiercely debated, until now.
New research, led by Dr Will Hutchison from the
School of Earth and Environmental Science at the University of St Andrews and
published in the journal Proceedings of
the National Academy of Sciences (Monday 30 December), reveals how the team
analysed ice core records from the 1831 event and identified a “perfect
fingerprint match” of the ash deposits.
“Only in recent years have we developed the ability
to extract microscopic ash shards from polar ice cores and conduct detailed
chemical analyses on them. These shards are incredibly minute, roughly
one-tenth the diameter of a human hair,” explained Dr Hutchison.
Dr Hutchison and his team were able to accurately
date and match the ice core deposits to Zavaritskii volcano on the remote,
uninhabited island of Simushir, part of the Kuril Islands. The islands are a
disputed territory between Russia and Japan. Currently controlled by Russia,
they operate as a strategic military outpost. During the Cold War, in a plotline
reminiscent of a Bond film, the Soviets used Simushir as a secret nuclear
submarine base, docking vessels in a flooded volcanic crater.
“We analysed the chemistry of the ice at a very high
temporal resolution. This allowed us to pinpoint the precise timing of the
eruption to spring-summer 1831, confirm that it was highly explosive, and then
extract the tiny shards of ash. Finding the match took a long time and required
extensive collaboration with colleagues from Japan and Russia, who sent us
samples collected from these remote volcanoes decades ago.
“The moment in the lab when we analysed the two ashes
together, one from the volcano and one from the ice core, was a genuine eureka
moment. I couldn’t believe the numbers were identical. After this, I spent a
lot of time delving into the age and size of the eruption in Kuril records to
truly convince myself that the match was real.”
This work highlights the Kuril Islands as a poorly
studied yet extremely productive volcanic region.
The volcano responsible for the 1831 eruption was
very remote, yet it had a significant global impact on climate and severe
consequences for human populations. Identifying the sources of these mystery
eruptions is crucial, as it allows scientists to map and monitor the regions on
Earth most likely to produce climate-altering volcanic events.
Dr Hutchison added, “There are so many volcanoes like
this, which highlights how difficult it will be to predict when or where the
next large-magnitude eruption might occur.
“As scientists and as a society, we need to consider
how to coordinate an international response when the next large eruption, like
the one in 1831, happens.”
原始論文：William
Hutchison, Patrick Sugden, Andrea Burke, Peter Abbott, Vera V. Ponomareva, Oleg
Dirksen, Maxim V. Portnyagin, Breanyn MacInnes, Joanne Bourgeois, Ben Fitzhugh,
Magali Verkerk, Thomas J. Aubry, Samantha L. Engwell, Anders Svensson, Nathan
J. Chellman, Joseph R. McConnell, Siwan Davies, Michael Sigl, Gill Plunkett. The 1831 CE mystery eruption identified as
Zavaritskii caldera, Simushir Island (Kurils). Proceedings of the National Academy of Sciences, 2025; 122 (1) DOI:
10.1073/pnas.2416699122
引用自：The
University of St Andrews. “St Andrews researchers solve 200 year volcanic
mystery”
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