When ocean accidents happen, submarine rescue often has much difficulty because of special environment of ocean and bad climate.

当海难事故发生时，由于海洋特殊的环境因素及恶劣的气候，此时的救援工作往往比较困难。

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Ancient submarine forest grew in alluvial-pluvial deposit in Holocene Changle group, and the growing era is damp and hot climate environment as about 7000 ~ 7500 years ago;

该海底古森林生长于全新世长乐组冲洪积层中，生长时代为距今约7000—7500 a，为湿热气候环境；

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Researchers are using a nuclear submarine to take them beneath the Arctic ice cap to study ocean currents that may have an effect on global climate.

CNN: Nuclear sub dives under the ice to explore climate change