在最深的藍洞中發(fā)現了距今8000年的碳
Carbon more than 8,000 years old has been found inside the world's deepest blue hole — the Yongle Blue Hole (YBH) — which was recently discovered in the South China Sea, according to journal JGR Biogeosciences.
據《JGR生物地球科學》雜志報道,最近在南海發(fā)現的世界最深的藍洞——永樂藍洞(YBH)內發(fā)現了8000多年前的碳。
Blue holes are marine caverns filled with water and are formed following dissolution of carbonate rocks, usually under the influence of global sea level rise or fall. What distinguishes them from other aquatic caverns is that they are isolated from the ocean and don’t receive fresh rainwater.
藍洞是由碳酸鹽巖溶解后形成的充滿水的海相洞穴,通常受到全球海平面上升或下降的影響。它們與其他水生洞穴的不同之處在于,它們與海洋隔絕,不接受新鮮的雨水。
They are generally circular, steep-walled and open to surface.
它們通常是圓形的,有陡峭的墻壁,并且對地面開放。
According to JGR Biogeosciences, researchers found low levels of dissolved organic carbon and high levels of dissolved inorganic carbon in YBH, both with radiocarbon ages of more than 6,000 years.
根據JGR生物地球科學,研究人員發(fā)現,YBH中溶解有機碳含量低,而溶解無機碳含量高,兩者的放射性碳年齡都超過6000年。
Such concentrations of carbon, usually found in deep marine holes like YBH, provide a natural laboratory to study carbon cycling and potential mechanisms controlling it in the marine ecosystem.
這種碳的濃度通常存在于深海中,如YBH,為研究海洋生態(tài)系統(tǒng)中的碳循環(huán)和控制碳循環(huán)的潛在機制提供了一個天然的實驗室。
YBH has a depth of 300 metres, far deeper than the previously recorded deepest blue hole, Dean’s Blue Hole in Bahamas, which had a depth of 202 metres.
YBH的深度為300米,遠比先前記錄的最深的藍洞——巴哈馬的迪恩藍洞(Dean's blue hole)深202米。
Though a largely enclosed geomorphology, YBH is influenced with some oceanic exchange in the surface water. However, like most blue holes, it is anoxic i.e. depleted of dissolved oxygen below a certain depth. This anaerobic environment is unfavorable for most sea life.
盡管YBH是一個大范圍封閉的地貌,但它也受到了地表水海洋交換的影響。然而,和大多數藍洞一樣,藍洞是缺氧的,即溶解氧在一定深度以下就會枯竭。這種厭氧環(huán)境對大多數海洋生物是不利的。
Low oxygen environments are an area of wide research in the aquatic ecosystem. According to the journal, such anoxic ecosystems are considered a critical environmental and ecological issue as they have led to several mass extinctions.
低氧環(huán)境是水生生態(tài)系統(tǒng)中一個廣泛研究的領域。據《華爾街日報》報道,這種缺氧的生態(tài)系統(tǒng)被認為是一個重要的環(huán)境和生態(tài)問題,因為它們已經導致了幾次大規(guī)模的滅絕。
The transition from aerobic to anaerobic environment adversely affects the biogeo-chemistry of the ocean. However, in blue holes, the transition happens within several hundred metres depth with lesser influences.
從好氧環(huán)境到厭氧環(huán)境的轉變對海洋生物地球化學產生了不利影響。然而,在藍洞中,這種轉變發(fā)生在幾百米深的范圍內,影響較小。
According to a related article published in Nature, this makes blue hole ecosystem a more accessible habitat to examine the physical and biological processes affecting carbon cycling and unusual ocean conditions.
根據《自然》雜志上發(fā)表的一篇相關文章,這使得藍洞生態(tài)系統(tǒng)成為一個更容易進入的棲息地,以研究影響碳循環(huán)和異常海洋條件的物理和生物過程。