深海熱泉會移除海洋中的碳

原文網址：www.sciencedaily.com/releases/2015/11/151102143735.htm

Deep-sea hydrothermal vents have carbon-removing properties

深海熱泉會移除海洋中的碳

University of Georgia Skidaway Institute of Oceanography scientist Aron Stubbins joined a team of researchers to determine how hydrothermal vents influence ocean carbon storage. The results of their study were recently published in the journal Nature Geoscience.

喬治亞大學斯基德维海洋研究所的科學家Aron Stubbins參與的研究團隊探討深海熱泉對海洋碳儲量會有何影響。他們的結果近日發表於期刊《自然－地質科學》之上。

Hydrothermal vents are hotspots of activity on the otherwise dark, cold ocean floor. Since their discovery, scientists have been intrigued by these deep ocean ecosystems, studying their potential role in the evolution of life and their influence upon today's ocean.

深海熱泉(hydrothermal vent)為既暗又冷的海床上少數活動劇烈的熱點。自從發現它們以來，科學家便對熱泉周邊的深海生態系統深感興趣，進行了無數研究以瞭解它們在生物演化上的地位，以及對現今海洋的影響。

Stubbins and his colleagues were most interested in the way the vents' extremely high temperatures and pressure affect dissolved organic carbon. Oceanic dissolved organic carbon is a massive carbon store that helps regulate the level of carbon dioxide in the atmosphere -- and the global climate.

Stubbins和他的同僚最感興趣的是極端高溫高壓的熱泉環境會如何影響溶解性有機碳。海洋的溶解性有機碳是座巨大的碳儲存庫，因此有助於調控大氣中的二氧化碳濃度，進一步影響全球氣候。

Originally, the researchers thought the vents might be a source of the dissolved organic carbon. Their research showed just the opposite.

起初，研究人員預計熱泉可能會是溶解性有機碳的來源之一，但研究結果呈現出來的卻恰好相反。

Lead scientist Jeffrey Hawkes, currently a postdoctoral fellow at Uppsala University in Sweden, directed an experiment in which the researchers heated water in a laboratory to 380 degrees Celsius (716 degrees Fahrenheit) in a scientific pressure cooker to mimic the effect of ocean water passing through hydrothermal vents.

現為瑞典烏普薩拉大學博士後研究員的Jeffrey Hawkes為此研究的主要研究人員，他於實驗室中利用高壓鍋具將海水加熱至380℃，來模擬海水經過熱泉系統時的情境，並觀察過程中會發生何種效應。

The results revealed that dissolved organic carbon is efficiently removed from ocean water when heated. The organic molecules are broken down and the carbon converted to carbon dioxide.

結果顯示海水加熱後會從中移除大多數的溶解性有機碳。這些有機分子被分解掉之後，其中的碳元素會轉變成二氧化碳。

The entire ocean volume circulates through hydrothermal vents about every 40 million years. This is a very long time, much longer than the timeframes over which current climate change is occurring, Stubbins explained. It is also much longer than the average lifetime of dissolved organic molecules in the ocean, which generally circulate for thousands of years, not millions.

若要讓所有海水都流經熱泉系統大約要花費4000萬年。Stubbins解釋說這是一段耗時甚久的歷程，跟眼下正發生的氣候變遷時間尺度相比而言要長得多。而這跟海洋中溶解性有機分子平均存在的時間相比也長了許多，它們通常以數千年的時間尺度循環，而非數百萬年。

"However, there may be extreme survivor molecules that persist and store carbon in the oceans for millions of years," Stubbins said. "Eventually, even these hardiest of survivor molecules will meet a fiery end as they circulate through vent systems."

「然而，或許海洋中存在有某些可稱作終極生存者的分子，它們能夠持有並儲存碳原子長達數百萬年。」Stubbins說。「然而，即便是所有分子中最頑強的倖存者，最終它們還是會在流經熱泉系統時燃燒殆盡。」

Hawkes conducted the work while at the Research Group for Marine Geochemistry, University of Oldenburg, Germany. The study's co-authors also included Pamela Rossel and Thorsten Dittmar, University of Oldenburg; David Butterfield, University of Washington; Douglas Connelly and Eric Achterberg, University of Southampton, United Kingdom; Andrea Koschinsky, Jacobs University, Germany; Valerie Chavagnac, Université de Toulouse, France; and Christian Hansen and Wolfgang Bach, University of Bremen, Germany.

Hawkes於他在參與德國奧爾登堡大學海洋地質化學研究團隊時進行了這項研究計畫。共同作者包括Pamela Rossel和Thorsten Dittmar(奧爾登堡大學)、David Butterfield(美國華盛頓大學)、Douglas Connelly和Eric Achterberg(英國南安普敦大學)、Andrea Koschinsky(雅德國各布大學)、Valerie Chavagnac(法國土魯斯大學)、Christian Hansen和Wolfgang Bach(德國不來梅大學)。

引用自：University of Georgia. "Deep-sea hydrothermal vents have carbon-removing properties." ScienceDaily. ScienceDaily, 2 November 2015.