浙江全新世海滩岩是目前公认的中国最北的海滩岩,对它的研究在古气候、古环境、古海面变化等方面都具有重要意义。笔者对浙江海滩岩进行了综合研究,揭示其古动物学、岩石学、矿物学、元素地球化学、氧碳稳定同位素和^(14)C测年等特征,...浙江全新世海滩岩是目前公认的中国最北的海滩岩,对它的研究在古气候、古环境、古海面变化等方面都具有重要意义。笔者对浙江海滩岩进行了综合研究,揭示其古动物学、岩石学、矿物学、元素地球化学、氧碳稳定同位素和^(14)C测年等特征,从中提取了古气候、古环境信息。研究表明,浙江海滩岩由8个岩石类型组成,其沉积可分两阶段8期:6.5—2.4 ka BP阶段(细分为6.5 ka BP,6.1—5.8 ka BP,5.5 ka BP,5.2—5.1 ka BP,4.8—4.1 ka BP,3.8 ka BP,3.5—2.4 ka BP 7期)和1.1 ka BP阶段(共8期),其所含动物遗骸具有较强烈的热带色彩,由δ^(18)O计算,中全新世海水温度高于现今3.25—4.25℃。展开更多
In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obt...In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obtained and studies wereconducted on the evolution of permafrost in Northeast China, but so far no systematic summary and review have been made.Based on sedimentary sequences, remains of past permafrost, paleo-flora and -fauna records, and dating data, permafrostevolution since the Late Pleistocene has been analyzed and reconstructed in this paper. Paleo-temperatures reconstructedfrom the remains of past permafrost and those from paleo-flora and -fauna are compared, and thus the southern limitof permafrost （SLP） in each climate period is inferred by the relationship of the permafrost distribution and the meanannual air/ground temperatures （MAAT/MAGT）. Thus, the evolutionary history of permafrost is here divided into fivestages： （1） the Late Pleistocene （Last Glaciation, or LG） （65 to 10–8.5 ka）, the Last Glaciation Maximum （LGM, 21–13 ka）in particular, the coldest period in the latest history with a cooling of about 6~10 °C, characterized by extensive occurrencesof glaciation, flourishing Mammathas-Coelodonta Faunal Complex （MCFC）, widespread aeolian deposits, and significantsea level lowering, and permafrost greatly expanded southwards almost to the coastal plains （37°N–41°N）; （2） the HoloceneMegathermal Period （HMP, 8.5–7.0 to 4.0–3.0 ka）, 3~5 °C warmer than today, permafrost retreated to about 52°N; （3） theLate Holocene Cold Period （Neoglaciation） （4.0–3.0 to 1.0–0.5 ka）, a cooling of 1~3 °C, some earlier thawed permafrost wasrefrozen or attached, and the SLP invaded southwards to 46°N; （4） the Little Ice Age （LIA, 500 to 100–150 a）, the latestcold period with significant permafrost expansion; and （5） climate warming since the last century, during which NortheastChina has undergone extensive permafrost degradation. The frequent and substantial expansions and retreats of permafrosthave greatly impacted cold-region environments in Northeast China. North of the SLP during the HMP, or in the presentcontinuous permafrost zone, the existing permafrost was largely formed during the LG and was later overlapped by thepermafrost formed in the Neoglaciation. To the south, it was formed in the Neoglaciation. However, many aspects ofpermafrost evolution still await further investigations, such as data integration, numerical reconstruction, and merging ofChinese permafrost history with those of bordering regions as well as collaboration with related disciplines. Of these, studies on the evolution and degradation of permafrost during the past 150 years and its hydrological, ecological, and environmentalimpacts should be prioritized.展开更多
在当前全球气候变化背景下,中科院战略性先导科技专项"应对气候变化的碳收支认证及相关问题"之"影响与适应任务群"主要以全新世大暖期为"相似型",研究全球平均增温约1°C—2°C情形下的我国环境...在当前全球气候变化背景下,中科院战略性先导科技专项"应对气候变化的碳收支认证及相关问题"之"影响与适应任务群"主要以全新世大暖期为"相似型",研究全球平均增温约1°C—2°C情形下的我国环境格局及其对陆地生态系统的可能影响,为人类适应提供自然背景及参照;探讨过去不同气候环境背景下人类的适应方式,揭示人类适应气候变化的规律和模式,为未来人类如何适应气候变化提供启示。通过近5年的工作,在自然背景研究方面,揭示出目前的全球增温有自然变暖的周期背景,且不同尺度的增温总体有利于我国季风区降水增加,导致森林面积扩大,我国北方沙漠区收缩,陆地生态系统碳储量增加。在人类起源与适应研究方面,获得了东亚地区现代人起源和迁徙的新证据,揭示出过去的气候变暖促进了农作物的栽培与驯化。8 ka BP—6 ka BP,稻作和旱作农业在空间上显著扩展,农业技术的进步促使史前人类在青藏高原大规模定居。一般情况下,过去寒冷的气候条件限制了人口发展,而相对暖湿的气候有利于人口的增加和文化的发展。研究同时显示,近70年来我国海岸带陆地面积由于人类活动加剧而增加近14 200 km^2。未来工作应加强高分辨率气候变化历史的定量重建,加强气候-环境-人类活动相互作用的机制等研究。展开更多
From the last deglaciation to the Holocene, the Greenland Ice Core (GISP2) δ 18O records as well as the records of ice-rafted debris on the surface of the North Atlantic have revealed a succession of sudden cooling e...From the last deglaciation to the Holocene, the Greenland Ice Core (GISP2) δ 18O records as well as the records of ice-rafted debris on the surface of the North Atlantic have revealed a succession of sudden cooling events on the centennial to millennial scales. However, the temperature proxy records are rarely studied systematically and directly to ensure that this air temperature cooling pattern simultaneously existed in the East Asian Region, in addition to the repeated pattern occurring in the Greater Atlantic Region. A peat cellulose δ 18O temperature proxy record proximately existing for 14000 years was picked up from the Hani peat in Jilin Province, China. It suggests by comparison that the sudden cooling events, such as the Older Dryas, Inter-Allerφd, Younger Dryas, and nine ice-rafted debris events of the North Atlantic, are almost entirely reiterated in the temperature signals of Hani peat cellulose δ 18O. These cooling events show that the repeatedly occurring temperature cooling pattern not only appeared in the North Atlantic Region in the high latitudes, but also in the Northwest Pacific Region in the middle latitudes. The climate change events marking the start of the Holocene Epoch, the Holocene Megathermal, the "8.2 kyr" event, the "4.2 kyr" event, the Medieval Warm Period, and the Little Ice Age are further discussed. The sensitivity response of Hani peat cellulose δ 18O to the land surface temperature and the reason for the age accuracy of peat cellulose 14C are also discussed based on the characteristics of the peat bog environment.展开更多
The formation and evolution of permafrost in China during the last 20 ka were reconstructed on the basis of large amount of paleo-permafrost remains and paleo-periglacial evidence, as well as paleo-glacial landforms, ...The formation and evolution of permafrost in China during the last 20 ka were reconstructed on the basis of large amount of paleo-permafrost remains and paleo-periglacial evidence, as well as paleo-glacial landforms, paleo-flora and paleofauna records. The results indicate that, during the local Last Glacial Maximum(LLGM) or local Last Permafrost Maximum(LLPMax), the extent of permafrost of China reached 5.3×106-5.4×106 km2, or thrice that of today, but permafrost shrank to only0.80×106-0.85×106 km2, or 50% that of present, during the local Holocene Megathermal Period(LHMP), or the local Last Permafrost Minimum(LLPMin). On the basis of the dating of periglacial remains and their distributive features, the extent of permafrost in China was delineated for the two periods of LLGM(LLPMax) and LHMP(LLPMin), and the evolution of permafrost in China was divided into seven periods as follows:(1) LLGM in Late Pleistocene(ca. 20000 to 13000-10800 a BP)with extensive evidence for the presence of intensive ice-wedge expansion for outlining its LLPMax extent;(2) A period of dramatically changing climate during the early Holocene(10800 to 8500-7000 a BP) when permafrost remained relatively stable but with a general trend of shrinking areal extent;(3) The LHMP in the Mid-Holocene(8500-7000 to 4000-3000 a BP)when permafrost degraded intensively and extensively, and shrank to the LLPMin;(4) Neoglaciation during the late Holocene(4000-3000 to 1000 a BP, when permafrost again expanded;(5) Medieval Warming Period(MWP) in the late Holocene(1000-500 a BP) when permafrost was in a relative decline;(6) Little Ice Age(LIA) in the late Holocene(500-100 a BP), when permafrost relatively expanded, and;(7) Recent warming(during the 20 th century), when permafrost continuously degraded and still is degrading. The paleo-climate, geography and paleopermafrost extents and other features were reconstructed for each of these seven periods.展开更多
文摘浙江全新世海滩岩是目前公认的中国最北的海滩岩,对它的研究在古气候、古环境、古海面变化等方面都具有重要意义。笔者对浙江海滩岩进行了综合研究,揭示其古动物学、岩石学、矿物学、元素地球化学、氧碳稳定同位素和^(14)C测年等特征,从中提取了古气候、古环境信息。研究表明,浙江海滩岩由8个岩石类型组成,其沉积可分两阶段8期:6.5—2.4 ka BP阶段(细分为6.5 ka BP,6.1—5.8 ka BP,5.5 ka BP,5.2—5.1 ka BP,4.8—4.1 ka BP,3.8 ka BP,3.5—2.4 ka BP 7期)和1.1 ka BP阶段(共8期),其所含动物遗骸具有较强烈的热带色彩,由δ^(18)O计算,中全新世海水温度高于现今3.25—4.25℃。
基金supported by the Subproject No. XDA05120302 (Permafrost Extent in China during the Last Glaciation Maximum and Megathermal)Strategic Pilot Science and Technology Program of the Chinese Academy of Sciences (Identification of Carbon Budgets for Adaptation to Changing Climate and the Associated Issues) (Grant No. XDA05000000)the auspices of the International Permafrost Association (IPA) Action Group on "Last Permafrost Maximum and Minimum (LPMM) on the Eurasian Continent"
文摘In Northeast China, permafrost advanced and retreated several times under the influences of fluctuating paleo-climatesand paleo-environments since the Late Pleistocene. During the last 60 years, many new data were obtained and studies wereconducted on the evolution of permafrost in Northeast China, but so far no systematic summary and review have been made.Based on sedimentary sequences, remains of past permafrost, paleo-flora and -fauna records, and dating data, permafrostevolution since the Late Pleistocene has been analyzed and reconstructed in this paper. Paleo-temperatures reconstructedfrom the remains of past permafrost and those from paleo-flora and -fauna are compared, and thus the southern limitof permafrost （SLP） in each climate period is inferred by the relationship of the permafrost distribution and the meanannual air/ground temperatures （MAAT/MAGT）. Thus, the evolutionary history of permafrost is here divided into fivestages： （1） the Late Pleistocene （Last Glaciation, or LG） （65 to 10–8.5 ka）, the Last Glaciation Maximum （LGM, 21–13 ka）in particular, the coldest period in the latest history with a cooling of about 6~10 °C, characterized by extensive occurrencesof glaciation, flourishing Mammathas-Coelodonta Faunal Complex （MCFC）, widespread aeolian deposits, and significantsea level lowering, and permafrost greatly expanded southwards almost to the coastal plains （37°N–41°N）; （2） the HoloceneMegathermal Period （HMP, 8.5–7.0 to 4.0–3.0 ka）, 3~5 °C warmer than today, permafrost retreated to about 52°N; （3） theLate Holocene Cold Period （Neoglaciation） （4.0–3.0 to 1.0–0.5 ka）, a cooling of 1~3 °C, some earlier thawed permafrost wasrefrozen or attached, and the SLP invaded southwards to 46°N; （4） the Little Ice Age （LIA, 500 to 100–150 a）, the latestcold period with significant permafrost expansion; and （5） climate warming since the last century, during which NortheastChina has undergone extensive permafrost degradation. The frequent and substantial expansions and retreats of permafrosthave greatly impacted cold-region environments in Northeast China. North of the SLP during the HMP, or in the presentcontinuous permafrost zone, the existing permafrost was largely formed during the LG and was later overlapped by thepermafrost formed in the Neoglaciation. To the south, it was formed in the Neoglaciation. However, many aspects ofpermafrost evolution still await further investigations, such as data integration, numerical reconstruction, and merging ofChinese permafrost history with those of bordering regions as well as collaboration with related disciplines. Of these, studies on the evolution and degradation of permafrost during the past 150 years and its hydrological, ecological, and environmentalimpacts should be prioritized.
文摘在当前全球气候变化背景下,中科院战略性先导科技专项"应对气候变化的碳收支认证及相关问题"之"影响与适应任务群"主要以全新世大暖期为"相似型",研究全球平均增温约1°C—2°C情形下的我国环境格局及其对陆地生态系统的可能影响,为人类适应提供自然背景及参照;探讨过去不同气候环境背景下人类的适应方式,揭示人类适应气候变化的规律和模式,为未来人类如何适应气候变化提供启示。通过近5年的工作,在自然背景研究方面,揭示出目前的全球增温有自然变暖的周期背景,且不同尺度的增温总体有利于我国季风区降水增加,导致森林面积扩大,我国北方沙漠区收缩,陆地生态系统碳储量增加。在人类起源与适应研究方面,获得了东亚地区现代人起源和迁徙的新证据,揭示出过去的气候变暖促进了农作物的栽培与驯化。8 ka BP—6 ka BP,稻作和旱作农业在空间上显著扩展,农业技术的进步促使史前人类在青藏高原大规模定居。一般情况下,过去寒冷的气候条件限制了人口发展,而相对暖湿的气候有利于人口的增加和文化的发展。研究同时显示,近70年来我国海岸带陆地面积由于人类活动加剧而增加近14 200 km^2。未来工作应加强高分辨率气候变化历史的定量重建,加强气候-环境-人类活动相互作用的机制等研究。
基金Supported by National Natural Science Foundation of China (Grant Nos. 40573004, 40673069, 40231007)
文摘From the last deglaciation to the Holocene, the Greenland Ice Core (GISP2) δ 18O records as well as the records of ice-rafted debris on the surface of the North Atlantic have revealed a succession of sudden cooling events on the centennial to millennial scales. However, the temperature proxy records are rarely studied systematically and directly to ensure that this air temperature cooling pattern simultaneously existed in the East Asian Region, in addition to the repeated pattern occurring in the Greater Atlantic Region. A peat cellulose δ 18O temperature proxy record proximately existing for 14000 years was picked up from the Hani peat in Jilin Province, China. It suggests by comparison that the sudden cooling events, such as the Older Dryas, Inter-Allerφd, Younger Dryas, and nine ice-rafted debris events of the North Atlantic, are almost entirely reiterated in the temperature signals of Hani peat cellulose δ 18O. These cooling events show that the repeatedly occurring temperature cooling pattern not only appeared in the North Atlantic Region in the high latitudes, but also in the Northwest Pacific Region in the middle latitudes. The climate change events marking the start of the Holocene Epoch, the Holocene Megathermal, the "8.2 kyr" event, the "4.2 kyr" event, the Medieval Warm Period, and the Little Ice Age are further discussed. The sensitivity response of Hani peat cellulose δ 18O to the land surface temperature and the reason for the age accuracy of peat cellulose 14C are also discussed based on the characteristics of the peat bog environment.
基金supported by the National Natural Science Foundation of China and Russian Foundation for Basic Research (FRBR) on “Formation, evolution and changes of Pleistocene cryogenic deposits in Eastern Asia” (Grant No. 41811530093)the Key Program of the Department of International Cooperation of the Chinese Academy of Sciences (Assessment of changes in permafrost in China, Russia and Mongolia and their impacts on key engineering infrastructures), (Permafrost extent in China during the Last Glaciation Maximum and Megathermal) of the Strategic Pilot Science and Technology Program of the Chinese Academy of Sciences (Grant No. XDA05120302)the CAS Overseas Professorship of Sergey S. Marchenko, and under the auspices of the International Permafrost Association Working Group on Global Permafrost Extent During the Last Permafrost Maximum (LPM)
文摘The formation and evolution of permafrost in China during the last 20 ka were reconstructed on the basis of large amount of paleo-permafrost remains and paleo-periglacial evidence, as well as paleo-glacial landforms, paleo-flora and paleofauna records. The results indicate that, during the local Last Glacial Maximum(LLGM) or local Last Permafrost Maximum(LLPMax), the extent of permafrost of China reached 5.3×106-5.4×106 km2, or thrice that of today, but permafrost shrank to only0.80×106-0.85×106 km2, or 50% that of present, during the local Holocene Megathermal Period(LHMP), or the local Last Permafrost Minimum(LLPMin). On the basis of the dating of periglacial remains and their distributive features, the extent of permafrost in China was delineated for the two periods of LLGM(LLPMax) and LHMP(LLPMin), and the evolution of permafrost in China was divided into seven periods as follows:(1) LLGM in Late Pleistocene(ca. 20000 to 13000-10800 a BP)with extensive evidence for the presence of intensive ice-wedge expansion for outlining its LLPMax extent;(2) A period of dramatically changing climate during the early Holocene(10800 to 8500-7000 a BP) when permafrost remained relatively stable but with a general trend of shrinking areal extent;(3) The LHMP in the Mid-Holocene(8500-7000 to 4000-3000 a BP)when permafrost degraded intensively and extensively, and shrank to the LLPMin;(4) Neoglaciation during the late Holocene(4000-3000 to 1000 a BP, when permafrost again expanded;(5) Medieval Warming Period(MWP) in the late Holocene(1000-500 a BP) when permafrost was in a relative decline;(6) Little Ice Age(LIA) in the late Holocene(500-100 a BP), when permafrost relatively expanded, and;(7) Recent warming(during the 20 th century), when permafrost continuously degraded and still is degrading. The paleo-climate, geography and paleopermafrost extents and other features were reconstructed for each of these seven periods.
