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1.
福建沿海全新世高温期的气候与海面变化   总被引:1,自引:3,他引:1  
王绍鸿  吴学忠 《台湾海峡》1992,11(4):345-352
本文综合分析了福建沿海全新世高温期的孢粉资料和海平面变化资料,建立了气温和海平面变化曲线.结果表明,8ka,B.P.前为气温和海平面上升期,8ka,B.P.以来为高温期和高海平面期,海平面升降与气温升降几乎同步.  相似文献   

2.
福建沿海全新世海平面变化   总被引:5,自引:0,他引:5  
曾从盛 《台湾海峡》1991,10(1):77-84
本文通过对严格筛选的61个海平面标志物进行研究,建立了福建沿海3个岸段的全新世海平面曲线。结果表明,在全新世海进过程中,海平面有过多次波动并且在6100,3100和1800a,B.P.前左右形成3次海平面高峰,但其高度分别不超过+3m,+2m和+1m;3个岸段海平面波动总趋势一致,但海平面的高度和变动幅度存在差异:闽东北沿海6100a,B.P.前左右的高海面比3100a,B.P.前左右的为高,闽中沿海则相反,其6100a,B.P.前左右的高海面比3100a,B.P.前的为低。  相似文献   

3.
南海北部是南海向陆地过渡的前锋关键地带和全球变化的敏感地区之一,受海平面变化的影响,该地区海平面标志物广泛发育,是开展过去海平面变化研究的理想区域。目前关于南海北部全新世海平面变化历史的认识依然存在一定分歧。基于此,通过新增6个珊瑚礁数据,并对南海北部已发表的海平面数据进行年代和高程校正,然后进行相互验证和可靠性分析。同时对监测记录较为连续的12个验潮站的现代海平面观测资料进行整理和进一步验证重建结果的可靠性。最后,根据汇编的679个校正和可靠性评估后的海平面数据,重建了南海北部全新世以来,尤其是最近2 000 a的海平面变化历史和变化特征。校正和评估后的数据显示:南海北部海平面从早全新世(8 211±128)cal a BP的-16.16 m快速上升到6 000~7 000 cal a BP的1.5~2.5 m,之后波动下降到现今海平面高度。其中在中全新世海平面保持高位震荡约2 600 a,而晚全新世南海北部过去2 000 a海平面整体呈现出阶段变化过程。首先,在公元0-350年呈下降趋势,然后在公元350-850年海平面快速上升,并在公元880年,海平面处于过去2 000 a的最高...  相似文献   

4.
通过对浙江沿海南部老鼠山遗址、中部灵山遗址、北部河姆渡遗址3个剖面土样的14 C测年和孢粉分析,揭示了15 226~5 550cal.aBP间孢粉记录反映的古环境及海平面变化,并简要分析二者对河姆渡文化形成发展和衰落的影响。结果表明:(15 226±256)~(5 550±48)cal.aBP大部分期间的沉积处于有海水入侵的环境或温暖的湿地沼泽环境,期间内发生两次海进和两次海退,海平面变化与气候变化基本一致,(15 226±256)~(13 600±130)cal.aBP为海进时期,气候温和略湿;(13 600±130)~(9 778±77)cal.aBP为海退阶段,气候温凉略干;(9 778±77)~(7 372±36)cal.aBP处于全新世大暖期,气候热暖潮湿,发生快速海进;(7 372±36)~(5 550±48)cal.aBP气候略转凉干,海平面下降,为河姆渡文化的形成发展与繁荣时期奠定了重要基础,后期咸潮与洪水内涝使环境恶化,河姆渡文化外迁并走向衰落时期,而浙江沿海古环境演化与海面波动引起的水环境变化是河姆渡文化兴衰的主要原因。  相似文献   

5.
利用福建沿海几个主要验潮站数据与法国空间局(CNES)AVISO多卫星融合资料分析了福建近海及其周边海域海平面的时、空变化特征及主要模态,并简要分析福建近海海平面变化趋势.得到如下结论:近54a(1960~2013年)福建沿海相对海平面上升约2 mm/a,福建沿海海平面变化存在显著的季节变化和2~3a及6~8a的年际变化特征,这与ENSO和长周期天文分潮的变化周期较为吻合;对比同期卫星高度计资料和潮位站资料(1993~2012年)发现,卫星高度计与潮位站分析结果基本一致;卫星高度计和潮位站分析结果表明,福建沿海区域海平面近20a平均线性变化趋势约为4 mm/a.  相似文献   

6.
沙坝湖海岸是一种重要的海岸类型。文章论述了粤西海岸全新世中期以来在海平面升降影响下沙坝湖地貌的发育过程,得出如下结论:距今7000a至5000a.海平面曾上升至+4m,由于大陆架泥沙的向陆堆积,形成了揭湖拦湾沙坝的后缘高突部分:以后海平面逐步下降至现今位置,它所形成的海退沙楔发育成低矮的向海沙坝和海滩;距今2000a,海平面趋于相对稳定;现今海平面微升,出现了海岸侵蚀。文章还对该地在海平面升降影响下的海岸泥沙运移机制以及海岸高海面堆积和现今海岸侵蚀现象作了解析。  相似文献   

7.
根据广东省沿海及珠江三角洲口门区17个验潮站资料,分析近40a(1955—1994年)平均相对海平面(RSL)变化特点,表明RSL存在振幅20—40cm的准同步变化和1.5—2.0mm·a-1上升率。广东沿海的RSL长期变化存在30—40a、振幅2—3cm的气候周期。珠江三角洲口门区的RSL变化深受珠江径流量变化的影响。径流量变化1000亿m3,各分流口门的年平均水位相应变化4—6cm。  相似文献   

8.
利用南海周边1989-2014年的潮汐资料和GPS长期观测资料,分析了南海周边相对海平面变化特征,以及2004年苏门答腊地震对该区域相对海平面变化的影响。研究结果表明,南海周边的相对海平面变化以上升为主,平均上升速率(4.53±0.20) mm/a,高于全球平均速率,且2004年后上升趋势加剧;南海周边相对海平面呈现6类较典型的变化特征,并存在与板块构造相对应的分区聚集现象,形成了中国东南和越南沿海、马来半岛、加里曼丹岛北部、菲律宾群岛等4个变化特征区。受2004年苏门答腊大地震的影响,马来半岛、南沙和西沙海域的地壳形变由上升趋势转为下沉,加剧了相对海平面的上升;中国东南沿海和菲律宾群岛受地震影响较小;越南沿海和加里曼丹岛北部区域的地震影响还有待进一步研究。  相似文献   

9.
冰消期海侵进程中南黄海潮流沙脊的演化模式   总被引:19,自引:0,他引:19  
南黄海东侧底形资料、浅地层剖面和YSDP-102钻孔揭示了冰消期海侵初期的古潮流沙脊群;南黄海QC2孔上部岩心又揭示了全新世中期的埋藏古潮流沙脊群;8422柱状岩心补充了若干现代南黄海沙脊群-苏北岸外辐射状沙脊群的特征,根据^14C测年、ESR测年及突变事件的分析,获得了不同时期沙脊形成的年代标尺,并获得以下结论:(1)沙脊沉积在层序地层中属上海侵体系域(UTST),其发育与海平面密切相关,最佳发育深度在-20--30m水深范围内,很少有超过-40m者,南黄海沙脊群随着陆架海侵进程自东向西跃迁,沙脊群广泛发育预示海平面的相对稳定或小幅度波动期;海平面急剧上升期实现了沙脊群的跃迁,南黄海沙脊演化可划分为3期;早期(约12-9ka)是据新仙女木期(YD)的海平面波动,以南黄海东侧古潮流沙脊群为代表,中期(约6.3-4ka)包括了中全新世高温期气候突然衰退事件(MHCR)的海平面波动,南黄海中部QC2孔揭露的埋藏潮流沙脊是这一期的代表;晚期为2ka至今的海平面缓慢波动期,以现代苏北岸我辐射沙脊群为代表。(2)潮流沙脊沉积物特征反映了水动力条件的变化,早期沙脊处于强动力作用下,随着海侵范围扩大,形成沙脊的动力条件愈来愈弱。(3)南黄海、东海与北黄海沙脊发育与演化有着相似的历史,因此,南黄海沙脊演化与海平面关系模式适应于整个中国东部陆架区。  相似文献   

10.
本文利用验潮站观测和卫星高度计数据,以及基于筛选的CMIP6的10个模拟性能较好的地球系统模式结果,对中国海平面的长期变化趋势,以及未来上升幅度进行了分析和预测。结果显示:(1)1960-2021年,中国沿海海平面呈加速上升趋势,上升速率为2.5 mm/a,加速度为0.06 mm/a2;1993-2021年上升速率为4.0 mm/a,高于全球同期3.3 mm/a的上升值。(2)1980-2021年,渤、黄海,东海和南海沿海海平面上升速率分别为3.5 mm/a、3.3 mm/a和3.6 mm/a,渤、黄海和南海沿海海平面上升速率较快,东海偏慢;渤、黄海沿海海平面在20世纪60-70年代上升较慢,80年代之后上升加快。(3)在中等情景(SSP2-4.5)和高情景(SSP5-8.5)下,2050年中国近海海平面将上升0.22 m(0.19~0.28 m)和0.24 m(0.21~0.33 m);到2100年,中国近海海平面将上升0.59 m(0.47~0.80 m)和0.83 m(0.64~1.09 m)。(4)2021-2040年,统计预测的海平面上升中值略接近数值模式低、中和高情景预测值...  相似文献   

11.
福建沿海晚更新世以来的海平面变化   总被引:4,自引:0,他引:4  
王绍鸿  杨建明 《台湾海峡》1994,13(2):166-175
本文选择了六类79个具有^14C年龄和准确高程的古海面标志物,按北,中,南三个岸段分别建立了三条相对海平面变化曲线,讨论了福建沿海晚更新世以来的海平面变化特征和规律,通过比较也分析了不同岸段新构造差异升降情况。  相似文献   

12.
广西钦州湾晚全新世红树林演变及对海平面变化的响应   总被引:2,自引:0,他引:2  
Mangroves, widely distributed along the coasts of tropical China, are influenced by Asia monsoon, relative sea level change and enhanced human activity. To predict the impacts of future climate change on mangrove ecosystems, it can be understood by reconstructing past mangrove dynamics using proxies preserved in coastal sediments. In this study, we quantitatively partitioned buried organic matter(OM) sources, collected from a vulnerable mangrove swamp in the Qinzhou Bay of northwestern South China Sea, using a ternary end-member mixing model of δ~(13)C and C:N values. Mangrove-derived OM(MOM) contribution was used as a tracer for mangrove development since 2.34 cal ka BP. This information, together with paleoclimate records(i.e.,speleothem δ~(18)O values, sea level change, grain size parameters) and human activity, was used to divide mangrove development into three stages during the late Holocene: relative flourish(2.34–1.13 cal ka BP), relative degradation(1.13–0.15 cal ka BP) and further degradation(0.15–0 cal ka BP). Before 1.13 cal ka BP, mangroves flourished with a high MOM contribution((88.9±10.6)%), corresponding to stable and high sea level under a warm and humid climate. After 1.13 cal ka BP, rapid fall in relative sea level coupled with the strengthening of the Asian winter monsoon, resulted in mangrove degradation and MOM reduction((62.4±18.9)%). Compared with air temperature and precipitation, the relative sea level fall was the main controlling factor in mangrove development before entering the Anthropocene(the time of the Industrial Revolution). After ~150 cal a BP, reclamation of mangrove swamps to shrimp ponds is the main factor causing mangrove degradation and MOM reduction.  相似文献   

13.
Using 110 newly revised Holocene sea level indicators categorized into three types, sediments (67), shelly cheniers (27) and oyster reefs (16), this paper firstly provides a Holocene relative sea level curve, based on multiple approaches of litho- and biostratigraphies and sedimentary faces analysis, for the west coast of Bohai Bay, China. Following considerations, including indicative meaning, the paleo tidal pattern and range and conversion from mean tidal level to mean sea level, an apparent relative mean sea level (RMSL) curve was further reconstructed. After systematical calibration using CALIB, those of the 48 reworked samples were further corrected for the residence-time effect. Similarly, the younger ages for another 35 samples were chosen at the subsample level. These result in a younger-oriented shift for about 0.5 ka. Three local spatial factors, including neotectonic subsidence (average rate about 0.1 mm/a), self-compaction of unconsolidated sediments (between a few decimeters to about 6 m) and subsidence due to groundwater withdrawal (between a few centimeters to about 2.5 m), were quantitatively corrected. Finally, the amended RMSL curve after eliminating all these local temporo-spatial factors is very likely to show non-existence of mid-Holocene highstand and imply potential influences of both ice-volume equivalent sea level and regional glacial isostatic adjustment. Although it is still unable to divide both global and regional factors, the slowdown of sea level rise, in 7.5–6.8 ka with a maximum height less than +1 m, may constrain the model effort in the near future.  相似文献   

14.
刘健  李绍全 《海洋科学》1998,22(3):54-57
论述了福建省莆田县忠门乡苦鹅头村东南海岸一套全新世含生物碎屑的砂、砾岩的沉积特征、沉积环境及其对海平面变化的反映。砂、砾岩层可划分成上、下两段,具有不同的成因。下段(0 ̄2.6m)为海滩沉积,形成于中全新世高海平面时期。上段(2.6 ̄8m)是全新世晚期(约3 ̄2ka BP)的风沙沉积,内部夹有两个弱土壤化层,表明在风沙沉积作用过程中有过两次短暂的气候波动。  相似文献   

15.
High-resolution Chirp profiling and coring reveals an elongated(ca. 400 km) Holocene Zhujiang River(Pearl River)-derived mud area(maximum thickness 20 m) extending from the Zhujiang River Delta, southwestward off the Guangdong coast, to the Leizhou Peninsula. Two depo-centers, one proximal and one distal, are identified. On the continental shelf off the west Guangdong Province, the mud is deposited in water depth shallower than 50 m; while to the southeast of the Zhujiang River Estuary, the mud area can extend to the-120 m isobath. A combined analysis with the stratigraphic sequences of other muddy deposits in the Western Pacific marginal seas(mainly Changjiang(Yangtze) and Huanghe(Yellow) Rivers derived) indicates that the initiation of the Zhujiang River muddy deposit can be further divided into two stages: Stage 1 is before the mid-Holocene sea-level highstand(ca. 7.0 cal. ka BP), the proximal mud was mostly deposited after 9.0 cal. ka BP, when the sea-level rose slowly after the Meltwater Pulse-1C; Stage 2, after the mid-Holocene sealevel highstand, clinoform developed on the continental shelf off the west Guangdong Province, extending ca. 400 km from the Zhujiang River Estuary. The proximal clinoform thins offshore, from ca. 10 m thickness around 5–10 m water depth to less than 1–2 m around 20–30 m water depth. In addition, we also find a developed distal clinoform in the east of the Leizhou Peninsula.  相似文献   

16.
The future regional sea level (RSL) rise in the western North Pacific is investigated by dynamical downscaling with the Regional Ocean Modeling System (ROMS) with an eddy-permitting resolution based on three global climate models—MIROC-ESM, CSIRO-Mk3.6.0, and GFDL-CM3—under the highest greenhouse-gas emission scenario. The historical run is forced by the air-sea fluxes calculated from Coordinated Ocean Reference Experiment version 2 (COREv2) data. Three future runs—ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL—are forced with an atmospheric field constructed by adding the difference between the climate model parameters for the twenty-first and twentieth century to fields in the historical run. In all downscaling, the RSL rise along the eastern coast of Japan is generally half or less of the RSL rise maxima off the eastern coast. The projected regional (total) sea level rises along the Honshu coast during 2081–2100 relative to 1981–2000 are 19–25 (98–104), 6–15 (71–80), and 8–14 (80–86) cm in ROMS-MIROC, ROMS-CSIRO, and ROMS-GFDL, respectively. The discrepancies of the RSL rise along the Honshu coast between the climate models and downscaling are less than 10 cm. The RSL changes in the Kuroshio Extension (KE) region in all downscaling simulations are related to the changes of KE (northward shift or intensification) with climate change.  相似文献   

17.
A multi-proxy study including sedimentological, mineralogical, biogeochemical and micropaleontological methods was conducted on sediment core PS69/849-2 retrieved from Burton Basin, MacRobertson Shelf, East Antarctica. The goal of this study was to depict the deglacial and Holocene environmental history of the MacRobertson Land–Prydz Bay region. A special focus was put on the timing of ice-sheet retreat and the variability of bottom-water formation due to sea ice formation through the Holocene. Results from site PS69/849-2 provide the first paleo-environmental record of Holocene variations in bottom-water production probably associated to the Cape Darnley polynya, which is the second largest polynya in the Antarctic. Methods included end-member modeling of laser-derived high-resolution grain size data to reconstruct the depositional regimes and bottom-water activity. The provenance of current-derived and ice-transported material was reconstructed using clay-mineral and heavy-mineral analysis. Conclusions on biogenic production were drawn by determination of biogenic opal and total organic carbon. It was found that the ice shelf front started to retreat from the site around 12.8 ka BP. This coincides with results from other records in Prydz Bay and suggests warming during the early Holocene optimum next to global sea level rise as the main trigger. Ice-rafted debris was then supplied to the site until 5.5 cal. ka BP, when Holocene global sea level rise stabilized and glacial isostatic rebound on MacRobertson Land commenced. Throughout the Holocene, three episodes of enhanced bottom-water activity probably due to elevated brine rejection in Cape Darnley polynya occured between 11.5 and 9 cal. ka BP, 5.6 and 4.5 cal. ka BP and since 1.5 cal. ka BP. These periods are related to shifts from warmer to cooler conditions at the end of Holocene warm periods, in particular the early Holocene optimum, the mid-Holocene warm period and at the beginning of the neoglacial. In contrast, between 7.7 and 6.7 cal. ka BP, brine rejection shut down, maybe owed to warm conditions and pronounced open-water intervals.  相似文献   

18.
福建晚更新世海侵问题探讨   总被引:1,自引:0,他引:1  
福建沿海在晚更新世大约距今90—80ka、70—60ka、44—39ka和34—20ka期间分别发生过4次海侵。最末一次海侵(距今34—20Ka)期间有过明显的海面下降波动,时间大约在距今28ka前后。  相似文献   

19.
根据舟山群岛峡道地区的钻孔资料,在有孔虫、花粉和沉积特性分析结果的基础上,分析了晚更新世海面变化,探讨了晚更新世末期峡道内的地面高程,进而根据海图量算结果,讨论了舟山群岛峡道底部的泥沙冲淤及其对浙闽沿海泥沙供给的影响。本文认为,晚更新世以来舟山群岛地区发生了三次海进海退,其中晚更新世末期低海面时,舟山群岛峡道高程约位于吴淞基面以下38m左右,全新世海侵以来,受峡道水动力的作用,除部分峡道内海湾发生淤积外,舟山群岛峡道底部发生了明显的冲刷,其最大冲刷厚度可达80m左右,为杭州湾乃至整个浙闽沿海提供了大量的泥沙  相似文献   

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