在最深的蓝洞中发现了距今8000年的碳

在最深的蓝洞中发现了距今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.

据《JGR生物地球科学》杂志报道，最近在南海发现的世界最深的蓝洞——永乐蓝洞(YBH)内发现了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.

蓝洞是由碳酸盐岩溶解后形成的充满水的海相洞穴，通常受到全球海平面上升或下降的影响。它们与其他水生洞穴的不同之处在于，它们与海洋隔绝，不接受新鲜的雨水。

They are generally circular, steep-walled and open to surface.

它们通常是圆形的，有陡峭的墙壁，并且对地面开放。

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.

根据JGR生物地球科学，研究人员发现，YBH中溶解有机碳含量低，而溶解无机碳含量高，两者的放射性碳年龄都超过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.

这种碳的浓度通常存在于深海中，如YBH，为研究海洋生态系统中的碳循环和控制碳循环的潜在机制提供了一个天然的实验室。

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的深度为300米，远比先前记录的最深的蓝洞——巴哈马的迪恩蓝洞(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.

尽管YBH是一个大范围封闭的地貌，但它也受到了地表水海洋交换的影响。然而，和大多数蓝洞一样，蓝洞是缺氧的，即溶解氧在一定深度以下就会枯竭。这种厌氧环境对大多数海洋生物是不利的。

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.

低氧环境是水生生态系统中一个广泛研究的领域。据《华尔街日报》报道，这种缺氧的生态系统被认为是一个重要的环境和生态问题，因为它们已经导致了几次大规模的灭绝。

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.

从好氧环境到厌氧环境的转变对海洋生物地球化学产生了不利影响。然而，在蓝洞中，这种转变发生在几百米深的范围内，影响较小。

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.

根据《自然》杂志上发表的一篇相关文章，这使得蓝洞生态系统成为一个更容易进入的栖息地，以研究影响碳循环和异常海洋条件的物理和生物过程。