Research progress of ocean drilling in the North Pacific Ocean: Paleoceanography and paleoclimate
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摘要: 北太平洋作为全球大洋环流的重要组成部分,在高低纬间热量和物质的传输与再分配方面起到重要的调控作用,进而影响到地球气候系统。基于过去50多年来的大洋钻探工作,前人在北太平洋地球科学的研究上取得了一系列的成果。本文回顾了北太平洋古海洋和古气候方面的研究进展,包括:(1)东亚夏季风和西部边界流演化,以及其对高低纬热量、水汽的传输;(2) 北太平洋中层水和深层水的性质变化、分布范围和驱动机制,以及冰期旋回中水体垂直交换作用的气候响应;(3) 风尘输入对亚洲内陆古环境的反映,及其对北太平洋生产力的铁肥效应。尽管前人针对上述科学问题都开展了相应的研究工作,但目前在对北太平洋上述几方面的认识上仍然存在着分歧。基于对前人研究的总结概括,本文最后提出了未来北太平洋研究的关键科学问题,强调了多圈层、多系统角度对深入认识过去地球气候系统变化的重要性,并对未来大洋航次开展的理想靶区进行了展望。Abstract: As an important part of global ocean circulation, the North Pacific Ocean plays a key role in regulating the transfer and redistribution of heat and matter between high and low latitudes, thus affecting the Earth’s climate system. Based on the ocean drilling programs over 50 years in the past, many achievements in geoscience have been made. We reviewed the progresses of paleoclimate research in the North Pacific in the following aspects: (1) the evolution of the East Asian summer monsoon and the western boundary current, as well as their contributions to the transportation of heat and water vapor between high and low latitudes in North Pacific; (2) changes in water property, distribution, and the driving mechanisms of the Pacific Deep Water and North Pacific Intermediate Water, as well as the climatic response of their interaction during glacial-interglacial cycles; (3) the response of aeolian flux to the Asian inland and its iron fertilization effect on the North Pacific productivity. Previous studies have addressed those scientific problems, uncertain issued remain controversial. We therefore proposed the key scientific issues for future research in the North Pacific Ocean, and emphasized the importance of multi-layer and multi-system perspectives for deciphering the past changes of the Earth's climate system. Finally, we suggested the ideal target areas for ocean drilling program in North Pacific in the future.
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Keywords:
- ocean drilling /
- East Asian summer monsoon /
- western boundary current /
- eolian dust /
- productivity /
- North Pacific
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海底地貌作为海洋构造运动的直接表征,对于海底资源调查、沉积过程和构造活动研究具有十分重要的科学意义[1]。近年来,国外众多学者围绕海底地貌特征做了一系列研究调查,Posamentier等[2]通过对印度尼西亚近海、尼日利亚和墨西哥湾3D地震数据的分析,识别出浊积水道、水道堤岸复合体、水道-朵体复合体、分流河道复合体和泥石流水道等5种沉积地貌单元。Francis等[3]通过解释巴布亚湾(GoP)地区多波束测深、地震数据以及测井岩心,识别到陆坡峡谷、滑塌沉积物等地貌单元类型,并对GoP海底地貌进行了广泛的观察、描述和解释。Hogan等[4]使用高分辨率地球物理资料和岩芯数据研究了巴伦支海西北部海底地貌,在研究区识别出流线型地貌、融水地貌和洞穴、冰山冲刷地貌类型。Seri等[5]利用宽扎盆地高质量三维地震、海底地球化学和基于卫星的表面浮油数据等综合分析,观察到麻坑、泥坑或沥青火山等海底地貌特征。由此,海底地貌已逐渐形成一个完整全面的体系(表1)。现有资料证明,琼东南盆地现今海底地貌结构分布复杂,国内众多学者利用多样化手段对琼东南海底地貌进行研究,罗进华等[6]利用自制水下机器人采集资料,对琼东南盆地深水区典型块体流沉积和浊流沉积特征进行描绘,深化了对琼东南盆地深水沉积体系的认识;朱友生[7]等利用工程调查船和自主式水下潜器调查结合的方式,研究海底表层沉积物类型、分布规律及工程地质特性。
表 1 常见海底地貌及特征描述Table 1. Description and features of typical seafloor topography一级分类 二级分类 特征描述 深水水道 单一型水道 深水水道从形态上有弯曲水道(弯曲度>1.2)和顺直水道(弯曲度<1.2)之分[8-9],是沉积物由浅海向
深海搬运的重要通道分支水道 分支水道常发育于海底水道的头部和趾部,似树枝状展布,总体发育规模较小[10] 水道堤岸复合体 外部形态呈“海鸥”翼状展布,由“U”型或“V”型水道和楔状堤岸组成[11] 水道-朵体复合体 头部多为单一水道或者多分支水道,末端常以朵叶状展布 海底滑坡 头部 海底滑坡的头部常可识别出陡崖、滑移块体、侧壁、犁式正断层等沉积构造 体部 体部常见的特征有:滑塌褶皱、剪切槽、滑塌块体 趾部 趾部区域常能识别出逆冲断层、挤压脊、侵蚀擦痕以及外逸块体 冲沟 冲沟是常见的小尺度地貌,相当于深水沉积输送体系的“毛细血管”[12],多由高速冲刷的悬浮颗粒导致 海底峡谷 海底峡谷常呈“V”或“U”型下切,侧壁较陡,主要以侵蚀或沉积为主。深水海底峡谷是良好的油气储层,
同时也可以记录完整的海洋地质环境变迁相关信息[13]海底麻坑 孤立麻坑 孤立麻坑表现为圆形或椭圆形,直径1~300 m[14],是由超压流体溢出海底时侵蚀
海底沉积物所形成的一种负地形[15]条带状麻坑 由若干个大小不一的麻坑组成的麻坑带,古水道和浅层气的逸散是形成条带状麻坑的主要因素[8,16] 周期阶坎 周期阶坎多为长波形、不对称展布,似正弦曲线多数向上游迁移,部分向下游迁移的新月形[17] 目前,国内大多数研究集中于琼东南盆地陆架区和现今海底构架体系,对陵水凹陷陆坡区海底地貌的精细定量刻画研究还不够完善。因此,本文利用高分辨率三维地震资料,对研究区现今海底地貌进行精细刻画和解释,分析其特征、分布和成因,这对于进一步认识南海北部海底地貌、预防海底地质灾害以及钻井平台选址都具有十分重要的意义。
1. 地质概况
琼东南盆地位于南海西北陆缘,是新生代伸展盆地,具有南北高、中间低的构造格局,地理上介于海南岛与西沙海槽之间,面积约8.3×104 km2[18-19],现今平均水深为500~1300 m[20],由越南和海南岛双物源供给,普遍发育陆坡滑坡、峡谷和海底扇等沉积体系[21-22](图1a)。研究区位于琼东南盆地陵水凹陷东南边缘,在中央凹陷与海南岛之间,属于盆地北部下陆坡地带,水域深度为1500~2200 m(图1),由于受多重因素的控制,发育相对复杂的沉积构造。
2. 数据和方法
本研究使用中国海洋石油集团有限公司提供的琼东南盆地陵水凹陷1000 km2高分辨率三维地震数据,地震数据面元为12.5 m×12.5 m(Inline×Crossline),时间采样率2 ms,所用地震数据的主频约为50 Hz,目的层平均速度约2000 m/s,垂向分辨率约为12.5 m,解释层位为现代海底层。
利用GeoFrame地震解释平台对研究区现今海底三维地震资料零相位初值拾取,解释完成的层位进行网格化处理,通过时深转换得到深度数据。宽度、坡度等数据的使用,是在地震剖面上读出测量对象的坐标,统计后计算得出。坡度数据需要在剖面上读取测量值的两处坐标,利用一定的数学公式计算出具体数值。尽管这种直接将地震剖面的测量数据转换为形态参数存在一定的不确定性,但目前这种方法在地震资料解释和浅层沉积体系研究中被广泛采用[14]。结合地震剖面、均方根振幅属性、倾角方位角属性以及Surfer软件绘制出现今海底地貌图(图1c),对研究区海底沉积地貌进行精细刻画和表征。
前人多使用侧扫声呐或多波束测深的方式对琼东南盆地陵水区域开展地貌分析[6-7,23],本文在前人的基础上结合三维地震技术对研究区开展研究。相较于多波束测深,三维地震能更好地将区域海底地貌与地震剖面振幅属性结合在一起,“由面入点”地分析各处地貌单元特征。根据Mosher使用两种方法对中央斯科舍陆坡海底地貌渲染的案例来看[24],相同工区环境下,多波束测深可以展示更大范围海底地貌特征,而三维地震数据具有更高的清晰度和分辨率,尤其是对单一微小的地貌。本研究虽然地震资料覆盖面积广,但除研究区内大型水道外,其余地貌特征均以微小形态展布,需要整合地震资料加以识别。因此,本文更适合使用三维地震数据研究区域海底地貌。
3. 地貌特征
琼东南盆地陆架边缘物源供给充足,沉积物受重力流沉积作用沿陆坡向下不断推进,沉积的过程中会发育复杂的海底地貌。综合研究区各类数据,识别出3种地貌单元:水道地貌单元、周期阶坎地貌单元和滑坡地貌单元。
3.1 水道地貌单元
3.1.1 水道
陆坡水道是在重力流作用下,将来自大陆架和上坡地区的大量沉积物输送至深海平原的重要通道[3]。研究区水道位于水深1200~1500 m,为长条状负地形,整体较为顺直(顺直型水道弯度一般小于1.2[8]),呈NE走向(图2),从水深1200 m处到水深1400 m处延伸超过14 km,发育面积为33.73 km2,宽度约0.75~3.62 km,往深海平原方向逐渐加宽,深度值分布于12.75~28.88 m(图3a)。水道发育区总体坡度为2°,随着水道深度的减小,两侧水道壁也在不断变化,西侧谷壁坡度为0.9°~11°,东侧谷壁较陡,坡度为1.6°~7.6°,整体而言,西侧谷壁比东侧谷壁坡度变化差异大(图3a-b)。水道根据其反射特性分为“U”型和“V”型水道,从剖面上看,C1是典型的“U”型水道,代表水道受低速浊流冲刷和物源缓慢沉积[25],水道内部呈强振幅、高连续的地震反射特征。随着坡度的减小,水道的类型由侵蚀型为主逐渐过渡到沉积型为主(图2)。
本研究选取3条典型测线(图2a),统计29条数据参数(宽度、深度、水道壁倾角和水道总体坡度),结合倾角属性平面图,计算和分析其几何构型,对水道的形态变化展开定量分析(图3a-b):
Ⅰ段水道整体宽深比较小,水道壁两侧坡度较陡,外形呈陡窄U形,两侧堤岸发育明显,表明此处重力流流速大,水动力作用较强,具有一定的侵蚀能力[26]。此段水道形成于限制性条件下,主要以侵蚀型水道为主(图2b-c)。
Ⅱ段宽深比明显大于Ⅰ段,外形呈宽缓U形,两侧堤岸逐渐变低,沉积作用明显,表明水道在此限制力减弱。当重力流流经Ⅱ段时,水动力作用较弱,水道逐渐向水平方向拓展,使此段以沉积型水道为主(图2c-d)。由于上陆坡长期的物源供给,加之水道末端滑塌物致使重力流改道,在研究区末端,水道有消亡的趋势。
水道C1发育位置靠近上陆坡区,由三维地震资料和多波束测深(图1b-c)可以看出,C1上部东北方向发育大型陆坡水道系统,此陆坡水道的形成改变了原有坡折地形,使陆架区大量碎屑物质通过陆坡水道搬运至区域内,同时在海平面波动、构造运动等外部因素的共同控制下,粗粒沉积物往下陆坡运移的过程中,会逐渐在此冲刷出水道C1。
3.1.2 冲沟-朵体复合体
研究区陆坡发育大型滑塌体系,其滑塌物往下坡滑移的过程中,在研究区发育3个典型冲沟-朵体复合体系,由西向东依次命名为G1、G2、G3。
冲沟G1位于水道C1东侧约6 km处,相对延伸较短,整体形态呈“U-W-U”变化,中部发育明显朵体,末端又汇聚成单一沟槽,表示可能受多期侵蚀的特征[27]。G1在研究区内宽深比平均值为138,最大宽度为0.77 km(位于水道前端)(图3c),末端出现轻度弯曲,弯曲度为0.66,剖面呈强振幅、高连续反射地震相,且G1附近观察到几个小型侵蚀洼地,但其侵蚀程度不明显(图4a-b)。
G2延伸长度覆盖整个工区,头部呈树枝状形态,发育多个规模大小相当的支谷(图4c),这些支谷在中间位置最终汇集到一条主谷。随着冲沟槽的生长发育,受断裂引导以及块体搬运、海流侵蚀等因素的影响,其逐渐与周围沟谷连通并合,规模逐渐增大,形成以单个具有天然堤的水道(图4d)。G2宽深比平均值为100,最大宽度处为0.62 km(图3d),末段主要表现为叶状朵体形态,朵体面积达11.11 km2,呈凹槽状展布。G2整体表现出强振幅、高连续的地震反射特征(图4e)。
G3在研究区内宽深比达123,由树枝状头部组成,头部发育众多支流和沟壑(图4c)(这些初期沟壑的发育是后期冲沟形成的重要机制),支流在中游汇聚成单一的冲沟(图4d)。G3的变化幅度最大,其最大宽度达0.75 km,最窄的地方不足0.25 km(图3e),主要表现为“U”型。冲沟下倾方向发育相对平缓的朵体沉积,可能含有相对较高的砂质含量(图4e)。
研究区冲沟末端朵叶是在重力流侵蚀能力变弱、加积作用变强之时,在地势相对平坦的环境下形成的薄而广的砂体,朵体边界一般呈逐渐过渡关系,这类朵叶形成于非限制条件下,分布范围受浊积体的含砂量和地形等因素控制。
结合图1b、1c可以看出,冲沟-朵体复合体G1—G3的形成主要由陆坡区滑坡2—4控制,从左到右依次发育且规模量庞大,由于滑坡发生后地形坡度陡峭,在满足滑坡发生的条件下,沉积物滑移过程中高速侵蚀海底形成大小不等的冲沟,即复合体G2、G3头部树枝状形态,而后不断侵蚀加深形成中段U形地貌,随着地形坡度的减缓,经过长距离搬运的上坡物源缓慢沉积在其末端,形成叶状朵体。
3.2 周期阶坎地貌
周期阶坎是超临界浊流转变为亚临界浊流过程中形成的一系列向上游迁移的、长波状(波长/波高>>1)的台阶地貌[28],其波长范围一般从几十米至几千米不等[29],广泛分布于琼东南盆地其他地区[17]。根据研究区周期阶坎发育位置的不同,可将其分为水道体系周期阶坎和滑坡体系周期阶坎两类。
水道体系周期阶坎分布在水道C1全段以及冲沟-朵体复合体的扇体部分,发育面积达75 km2,平均发育坡度为1.3°,其波长为0.03~3.56 km,波高分布于1.2~5.44 m,具有独特的阶梯状形态。水道体系内周期阶坎底形普遍具有不对称特性,呈现出迎流面较长、背流面较短的形态,多数似月牙形向上游迁移,部分向下游迁移[17]。其地震剖面表现为强振幅、高连续的地震反射特征(图5b)。西侧堤岸形成的周期阶坎,其波峰和波谷的趋势与水道内部呈亚平行展布(图5a)。
滑坡体系周期阶坎多以簇或场的形式分布在区域内东西两侧滑坡堆积地带,发育面积约250 km2,平均发育坡度为1.3°,其波长为0.04~5.14,且总体上从上坡往深海方向有逐渐增大的趋势,波高为1.66~4.75,具有高度不对称的特征(图5e)。
不同区域和位置的波具有不同的波长和波高,滑坡体系的波长相较高于水道体系,且其平均波高也比水道体系的要高(表2、图5)。一般来说,更陡峭的斜率和更高密度的弗劳德数将有利于周期阶坎的形成。当地形坡度较大时,重力作用占主导,高密度流体处于不断加速过程,以侵蚀堆积作用为主[30]。而当地形坡度变化减缓时,高速沉积物流体从上陆坡逸散开来,浊流在海底扩散并产生水跃现象,在区域内形成周期阶坎地貌,然后受到水跃消能作用的影响,加之地形坡度不足以支撑流体转化作用的消失,周期阶坎底形逐渐消失。
表 2 研究区内周期阶坎发育主要参数Table 2. Measurements of the cyclic steps in the study area发育
体系发育位置 沉积区特征 周期阶坎基本特征 面积/km2 坡度/(°) 形态 波长/km 波高/m 水道
体系水道 55.92 1.33 长条状 0.03~3.56 1.2~5.44 冲沟-朵体带 19.18 1.04 叶状 0.05~2.06 1.88~2.06 滑坡
体系西侧滑塌区 87.06 1.41 分散展布 0.38~4.24 2.8~5.36 东侧滑塌区 157.82 1.12 分散展布 0.04~5.14 1.66~4.75 3.3 滑坡地貌单元
根据研究区滑坡发育的位置及滑块体运动的方向可分为水道壁滑塌和陆坡滑塌体。水道C1末端西侧谷壁受到深水重力流长期冲刷侵蚀,造成水道壁重力失稳向水道内部滑塌。陆坡重力失稳,滑动、滑塌向下部运动形成的滑块体,具有朵状几何外形,滑块体顺滑移面滑动,并发生一定程度的旋转,内部具有杂乱形态特征[8]。研究区处于陆架坡折带滑坡2—4的体部-趾部区域(图1b),因此能够识别出沉积物滑移所形成的挤压脊、舌状体。
3.3.1 水道壁滑塌
水道壁滑塌是水道堤岸在重力流的作用下沿水道壁侧向垮塌的一种现象,在其滑塌过程中会对基底及周围地层产生较强的侵蚀作用,滑塌方向一般与水道的展布方向垂直。
水道C1末端的滑塌沉积在平面上呈半圆或扇形(图6a),其滑塌方向的堆积物呈波浪式起伏形态,滑塌体厚度约35 m,面积达12.19 km2,占比水道总面积的36%。西侧水道壁在发生滑塌之前,坡度始终保持在3°~8°之间,在滑塌发生后,骤然转变为0.8°~1.1°(图3b),这就表明水道壁倾斜程度是造成滑塌发生的重要条件之一。滑塌体内部为杂乱反射,具有强振幅、高连续性的地震反射特征(图6b)。水道壁滑塌过程中,滑塌物受地形控制影响,停止向前搬运,而此时滑塌产生的动能并未减小,因此会产生严重的挤压作用,形成规律起伏的挤压褶皱(图6b)。
由图1b可以观察到,水道C1的西北方向陆坡区发育有滑坡1,滑坡1的沉积物流向趋近于水道壁滑塌点,推测认为,水道发生滑塌的条件除了水道壁倾斜程度大之外,还可能由于滑塌点堤岸物源不断加积所导致。水道发育初期,水道堤岸到底部高度逐渐增大,在重力流与海水冲刷作用下,水道堤岸愈发不稳定,通常这个时期水道堤岸发生滑塌的可能性增大。在滑塌发生后,滑塌沉积物可能导致水道内部重力流流速减慢,更易于在轴部形成沉积,在重力流较大的条件下,最终可能形成溢岸流。滑塌沉积可能导致该段水道逐渐被废弃。
3.3.2 陆坡滑塌体
(1)舌状体
舌状体是MTDs在趾部区的产物,它的存在反映了滑坡体逐渐向深海平原消亡的过程[23]。区域内舌状体以叶状形态展布,外部表现为起伏波动较大的鼓丘状地形(图1c),发育面积约105 km2,高出研究区其余地形约75 m,平均坡度2°。舌状体振幅频率较强表明此处岩性差异大,以重力流发育为主(图7a)。剖面强振幅,内部呈杂乱反射,推测为上陆坡滑移物的产物(图7c)。
舌状体的表面还发育有小型沟槽,其平均长度为5.4 km,整体宽度趋近于0.6 km,平均切入深度为5 m,具有明显的V形横截面(图7c),往深水方向无明显加宽趋势。这样的冲沟可能是由悬浮的沉积物流形成的,因为强烈的冲刷可能会使沉积在槽口的沉积物重新悬浮起来,另外此处地形比区域外其他地方高,更易引发密集的浊流冲刷。
现今陆坡区沉积物源在水动力的作用下往深海方向滑移,由于受下伏地层早期滑塌搬运堆积的影响,沉积物在此处受阻,在二次沉积的作用下,物源堆积在此处,覆盖在原有滑塌堆积物上,形成一个鼓丘状地形。推测认为,舌状体物源与上陆坡滑塌区物源相一致。
(2)挤压脊
挤压脊往往出现在MTDs的趾部区(图7b、d)。随着滑坡物质的动能逐渐减小,沉积滑移过程中的挤压作用和来自下伏未扰动地层的摩擦力,使得此处常常形成一些褶皱及伴生的逆冲断层,产生一系列叠瓦状逆冲构造;如果再失去流体物质,则易形成长条形塑性横向脊-挤压脊[6]。然而,由于剪切面的局部地形变化或流动障碍,它们也有可能出现在其他地方[31]。挤压脊通常与泥石流沉积物有关,并且发生在MTDs以不受限制的方式自由散布,形成凸下坡。叶状形态的地方,其通常垂直于最大压缩应力定向的主要流动方向[32]。当地形坡度较大或者地形隆起使块体向前搬运时受阻,地层会受到更严重的挤压作用,容易形成规模较大的挤压脊。
由于研究区处于琼东南陆架破折带滑坡体系的体部-趾部区域,所以能够观察到大规模挤压脊构造大多分布在东西两侧陆坡滑塌区域,形似海水波浪,呈均匀凹凸起伏状,具有强振幅、高连续性的地震反射特征(图7d),这是在外流块停留在海底时犁入下面的沉积物所形成的。挤压脊的上倾边缘沿SE方向倾斜,说明水流动力足够强,流体所携带的泥沙等碎屑物质能量强,背部挤压脊较为密集,越往南部,越来越稀疏,水动力逐渐减弱[17]。
4. 成因
4.1 滑坡为引
滑坡在海底陆坡区域内很常见,特别是诸如快速沉积、细粒沉积物或破裂岩石等弱地质材料受到地震、海啸和内部高孔隙度压力等环境应力条件下,下坡分量超过抵抗应力时,地层沿着一个或几个凹槽的滑动面移动。
琼东南盆地现今陆架坡折平均坡度在4°以上,局部可达10°,平均宽度约15 km,且坡度越陡,陆坡宽度越窄[33],这更有利于滑坡的形成。前人研究表明,琼东南盆地北部陆坡自5.5 Ma以来发育多期典型叠置的滑坡体系,且发育规模大、延伸距离远[34],至今尚可以清晰地观察到海底滑坡发生后形成的弧形陡坎(图1b)。琼东南盆地北部陆坡滑坡是造成下部研究区海底地貌形成的重要原因之一。由图1b可以看出,研究区上部坡折带多发育峡谷、沟谷、浊积扇等深水沉积类型,受海平面升降、物源供应以及陆坡坡度变化等多重因素影响,陆坡沉积物发生重力失稳,引发多期次滑坡。当滑坡发生时,海底块体被迅速移走并运送至更深的水域,粒度较大的沉积物在高速运移过程中冲刷出初期水道,在后期浊流的二次搬运以及陆坡水道长期稳定的物源供给作用下,水道C1逐渐加大变宽,形成现今地貌。其中一些块体在长距离搬运下沉积在研究区,在其内部形成挤压脊等沉积构造,另一部分以较高的流速加之水跃的发生,在区域内广泛发育周期阶坎。由此在研究区内形成了复杂、综合的海底地貌特征。
4.2 物源加持
近2~4 Ma以来,在气候的影响下,地球上无论构造稳定区还是构造活动区,沉积速率均突然增加了2~10倍。琼东南盆地大部分沉积物厚度达1000 m,呈披覆式发育[35]。
琼东南盆地主要物源供给体系包括红河物源、海南岛物源和越南中部物源三大体系[36]。根据IODP349、367-368X航次钻探研究发现,上新世(5.3 Ma)至今,南海海域夏季风盛行,降雨量增大,陆上河流的径流量增大,搬运能力加强,运送到陆坡的陆源碎屑物质增加[37],该时期,琼东南盆地所接收沉积物通量增大,平均可达20×103 km3/Ma,且自新生代以来,琼东南盆地伸展作用明显,形成较大的沉积物可容空间,引起了陆架破折的北向迁移。通过研究琼东南盆地不同区域稀土元素特征,可以看出第四纪沉积物源主要受海南岛影响,海南岛是该地区持续稳定的源区[38],沉积物供给量一直呈递增趋势,可达15~45 km3/Ma [39],而红河输送量稍有减小,最大为38 km3/Ma[40]。因此认为,海南岛物源体系控制着琼东南盆地东北部陆架边缘轨迹迁移演化。
综上所述,琼东南盆地自上新世以来所接收的沉积物量大,致使研究区西北部陆架边缘体系向前推进。随着海平面升高,沉积物供给速率与可容纳空间增长速率相差不大时,陆架边缘发育地层垂向叠加的加积沉积,当上陆坡的坡度达到一定程度后,沉积物更容易失稳[41],形成了峡谷和重力流广泛发育的陡峭地形,影响了研究区海底地貌的形成。
4.3 海平面升降
海平面升降会改变陆坡沉积物的水动力条件、沉降速率和剪切强度等参数,导致沉积物失稳,增加沉积物向深海方向的供给。全球海平面的波动是由海洋水量或海洋盆地体积的变化引起的,通常可以调节源汇系统的连通性并改变沉积物供应和运输距离。一般情况下,当海平面下降时,沉积物会远离陆地,靠近深水区,这就为海底地貌的形成提供了物源条件(图8)。特别是海平面自1 Ma以来急剧波动,频繁上升和下降,这可能与冰期到间冰期的气候循环有关[42]。低海平面或海平面急剧上升会影响沉积物稳定性。
根据ODP 1148的海平面记录[43],琼东南盆地的海平面呈现快速的周期性变化,振荡幅度和频率很高,且琼东南盆地现今陆架宽达100~450 km[44],是世界上最宽广的陆架之一,一旦海平面发生微小的变化都会引起海岸线大规模的进退,这对邻近深海区的沉积物供应变化造成巨大影响[45]。因此,快速的海平面波动可能是研究区多类第四纪沉积地貌形成的关键机制。
海平面变化在整体上对陆坡区的水深有直接的影响[33]。晚中新世以来琼东南盆地发生过3次大的海退事件,海南岛隆起和红河提供了充足的沉积物来源,向深海方向强烈的进积作用使沉积体在一定坡度下自身重力不断增加[46]。因此,认为海平面的变化是触发研究区上陆坡滑塌沉积的关键外部因素,导致上陆坡沉积物滑移至此,形成各种沉积地貌单元。
5. 结论
(1)高分辨率三维地震资料及综合数据的利用对研究区海底地貌的识别效果显著,研究区现今海底受深水重力流及流体作用的影响,主要发育水道、周期阶坎和陆坡滑坡体3种地貌单元。
(2)研究区深水水道主要分为水道和水道-朵体复合体两种地貌,水道C1是宽深比为31.5~232的大型水道,主要由陆坡水道运输的碎屑物质冲刷而成,同时,水道C1末端还发育半圆或扇形的水道壁滑塌;冲沟-朵体复合体G1—G3由陆坡滑坡系统控制而成,末端可见明显朵体发育,推测由坡折处滑坡2—4导致。
(3)在研究区水道和滑坡体系可以识别到周期阶坎,且滑坡体系的波长和平均波高高于水道体系。同时,研究区位于陆架滑坡体系的趾部区域,可识别出挤压脊、舌状体等构造。
(4)研究区现今海底地貌主要由上陆坡区滑塌引起,伴随着第四纪至今物源供给增强,以及海平面升降等多重因素,形成如今的综合型海底地貌。
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图 2 晚第四纪东亚夏季风记录对比
a. 黄土10Be记录[27];b. 黄土碳酸盐碳同位素记录[28];c. 黄土频率磁化率记录[29];d. 长江流域降水记录[30];e.九州岛沉积物通量,指示日本九州岛降水记录[31];f. 日本东部孢粉记录。RC1499孔(青黄色)和MD01-2421孔(深绿色)[32-33];g. 中国东部石笋氧同位素记录[24];h. 珠江流域叶蜡氢同位素记录[34]。灰色条带指示海洋氧同位素阶段。
Figure 2. Comparison of East Asian summer monsoon records in East Asian continent and surrounding oceans reflected from different data
a. Loess 10Be data[27]; b. Loess carbonate δ13C data[28]; c. Loess magnetic susceptibility (χfd) data[29]; d. Yangtze River runoff data[30]; e. Sediment flux of Kyushu as rainfall data[31]; f. Pollen records in eastern Japanese in Site RC1499 (bluish yellow) and MD01-2421 (dark green)[32-33]; g. Chinese cave δ18O data[24]; h. Pearl River leaf wax δ2H data[34]. Grey bars show Marine Oxygen Isotope Stage (MIS).
图 3 北太平洋海表温度及表层环流
地图使用Ocean Data View生成[14]。KmC:勘察加流,OC:亲潮,AC:阿拉斯加暖流,CC:加利福尼亚流,KC:黑潮,KCE:黑潮延伸流。
Figure 3. Sea surface temperature and surface circulation in the North Pacific
Map is generated using Ocean Data View[14]. KmC: Kamchatka Current, OC: Oyashio Current, AC: Alaska Current, CC: California Current, KC: Kuroshio Current, KCE: Kuroshio Current Extension.
图 4 北太平洋中层水(NPIW)演化及其气候响应(850 ka以来)
a. LR04 底栖δ18O[75];b. 大气CO2含量[76];c. U1343站位太平洋深层水(PDW)上涌指数[1];d. NPIW强度变化[1];e. 白令海U1345站位自生εNd记录[73];f. 相对海平面变化[77-78],−50 m虚线代表白令海峡现今深度。
Figure 4. The evolution of North Pacific Intermediate Water (NPIW) and its climatic responses
a. LR04 benthic foraminiferal δ18O stack[75]; b. Atmospheric CO2 concentration[76]; c. Upwelling index of Pacific Deep Water (PDW) from site U1343[1]; d. NPIW intensity1]; e. Site U1345 authigenic εNd records from Bering Sea[73]; f. Relative Sea Level[77-78], the dotted line at −50 m represent modern Bering Strait depth.
图 5 北太平洋风尘通量记录对比
a. LR04 底栖δ18O[75],b. ODP 885/886风尘累积速率[106],c. ODP 885A赤铁矿与针铁矿相对含量(RelHm+Gt)[108],d. ODP 885A化学风化指数(CIA)[108],e和f. ODP 885/886和ODP 1208风尘通量[110],g. ODP 1208蛋白石通量[110]。
Figure 5. The comparison of aeolian flux in North Pacific sedimentary cores
a. LR04 benthic foraminiferal δ18O stack[75], b. Eolian dust mass accumulation rate from ODP 885/886[106], c. Relative concentration of hematite and goethite (RelHm+Gt) from ODP 885A[108], d. Chemical index of alteration (CIA) from ODP 885A[108], e and f. dust flux of ODP 885/886 and ODP 1208, respectively[110], g. Opal flux of ODP 1208[110].
图 6 北太平洋生产力变化模式
a. LR04 底栖δ18O[75],b. ODP 882蛋白石通量[61],c. ODP 882 Ba/Al [126],d. U1342 Si/Ti比值 [132],e. U1342 Fe/Ti比值[132],f. U1417生物硅含量(蓝色)和放射虫丰度(天蓝色)[134],g. 粗砂含量[134]。
Figure 6. The Patterns of productivity change in the North Pacific
a. LR04 benthic foraminiferal δ18O stack[75], b. Opal flux from ODP 882[61], c. Ba/Al records from ODP 882[126],d. Si/Ti records from U1342 132], e. Fe/Ti records from U1342[132], f. Biogenic silica (blue line) and diatom concentration (sky blue line) from U1417, respectively[134], g. Coarse sand content from U1417[134].
图 7 北太平洋多圈层耦合过程示意图
EASM:东亚夏季风,KC:黑潮,KCE:黑潮延伸流,NPIW:北太平洋中层水,PDW:太平洋深层水。
Figure 7. Diagram of multilayer coupling processes in the North Pacific Ocean
EASM: East Asian Summer Monsoon, KC: Kuroshio Current,KCE: Kuroshio Current Extension, NPIW: North Pacific Intermediate Water, PDW: Pacific deep water.
表 1 北太平洋古海洋与古气候大洋钻探航次
Table 1 The ocean drilling expeditions in the North Pacific
航次 钻探区域 主要研究目标 钻探站位 时间 Leg 86/88 西北太平洋 风尘、黑潮延伸流 576—581 1982 Leg 145 亚北极太平洋 风尘、NPIW 881—887 1993 Leg 198 沙莰基隆起 深水环流 1207—1214 2001 323 白令海 NPIW U1339—1345 2009 341 阿拉斯加大陆边缘 NPIW U1417—1421 2013 346 日本海 东亚季风 U1422—1430 2013 -
[1] Worne S, Kender S, Swann G E A, et al. Coupled climate and subarctic Pacific nutrient upwelling over the last 850, 000 years [J]. Earth and Planetary Science Letters, 2019, 522: 87-97. doi: 10.1016/j.jpgl.2019.06.028
[2] Jaccard S L, Haug G H, Sigman D M, et al. Glacial/interglacial changes in subarctic north pacific stratification [J]. Science, 2005, 308(5724): 1003-1006. doi: 10.1126/science.1108696
[3] Takahashi K, Ravelo A, Alvarez-Zarikian C. Pliocene-Pleistocene paleoceanography and climate history of the Bering Sea[R]. Scientific Prospectus, IODP, 323, 2009: 3-4,doi: 10.2204/iodp.sp.323.2009.
[4] Gray W R, Rae J W B, Wills R C J, et al. Deglacial upwelling, productivity and CO2 outgassing in the North Pacific Ocean [J]. Nature Geoscience, 2018, 11(5): 340-344. doi: 10.1038/s41561-018-0108-6
[5] Paulmier A, Ruiz-Pino D. Oxygen minimum zones (OMZs) in the modern ocean [J]. Progress in Oceanography, 2009, 80(3-4): 113-128. doi: 10.1016/j.pocean.2008.08.001
[6] Schmidtko S, Stramma L, Visbeck M. Decline in global oceanic oxygen content during the past five decades [J]. Nature, 2017, 542(7641): 335-339. doi: 10.1038/nature21399
[7] Deutsch C, Brix H, Ito T, et al. Climate-forced variability of ocean hypoxia [J]. Science, 2011, 333(6040): 336-339. doi: 10.1126/science.1202422
[8] Shao Y P, Wyrwoll K H, Chappell A, et al. Dust cycle: An emerging core theme in Earth system science [J]. Aeolian Research, 2011, 2(4): 181-204. doi: 10.1016/j.aeolia.2011.02.001
[9] Forster P, Ramaswamy V, Artaxo P, et al. Changes in atmospheric constituents and in radiative forcing[C]//Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press, 2007: 129-234.
[10] Martin J H. Glacial-interglacial CO2 change: The iron hypothesis [J]. Paleoceanography, 1990, 5(1): 1-13. doi: 10.1029/PA005i001p00001
[11] Mitchell B G, Brody E A, Holm-Hansen O, et al. Light limitation of phytoplankton biomass and macronutrient utilization in the Southern Ocean [J]. Limnology and Oceanography, 1991, 36(8): 1662-1677. doi: 10.4319/lo.1991.36.8.1662
[12] Li D W, Zheng L W, Jaccard S L, et al. Millennial-scale ocean dynamics controlled export productivity in the subtropical North Pacific [J]. Geology, 2017, 45(7): 651-654. doi: 10.1130/G38981.1
[13] Lam P J, Robinson L F, Blusztajn J, et al. Transient stratification as the cause of the North Pacific productivity spike during deglaciation [J]. Nature Geoscience, 2013, 6(8): 622-626. doi: 10.1038/NGEO1873
[14] Schlitzer R. Ocean data view[EB/OL]. 2022(2022-04-04). https://odv.awi.de.
[15] Ogi M, Tachibana Y. Influence of the annual Arctic Oscillation on the negative correlation between Okhotsk Sea ice and Amur River discharge [J]. Geophysical Research Letters, 2006, 33(8): L08709. doi: 10.1029/2006GL025838
[16] Shcherbina A Y, Talley L D, Rudnick D L. Direct observations of North Pacific ventilation: Brine rejection in the Okhotsk Sea [J]. Science, 2003, 302(5652): 1952-1955. doi: 10.1126/science.1088692
[17] Emile-Geay J, Cane M A, Naik N, et al. Warren revisited: Atmospheric freshwater fluxes and "Why is no deep water formed in the North Pacific'' [J]. Journal of Geophysical Research:Oceans, 2003, 108(C6): 3178. doi: 10.1029/2001JC001058
[18] Wang P X, Wang B, Cheng H, et al. The global monsoon across time scales: Mechanisms and outstanding issues [J]. Earth-Science Reviews, 2017, 174: 84-121. doi: 10.1016/j.earscirev.2017.07.006
[19] Maher B A, Thompson R. Oxygen isotopes from Chinese caves: records not of monsoon rainfall but of circulation regime [J]. Journal of Quaternary Science, 2012, 27(6): 615-624. doi: 10.1002/jqs.2553
[20] Parker S E, Harrison S P, Comas-Bru L, et al. A data-model approach to interpreting speleothem oxygen isotope records from monsoon regions [J]. Climate of the Past, 2021, 17(3): 1119-1138. doi: 10.5194/cp-17-1119-2021
[21] Caley T, Roche D M, Renssen H. Orbital Asian summer monsoon dynamics revealed using an isotope-enabled global climate model [J]. Nature Communications, 2014, 5: 5371. doi: 10.1038/ncomms6371
[22] Liu J B, Chen J H, Zhang X J, et al. Holocene East Asian summer monsoon records in northern China and their inconsistency with Chinese stalagmite δ18O records [J]. Earth-Science Reviews, 2015, 148: 194-208. doi: 10.1016/j.earscirev.2015.06.004
[23] Rao Z G, Jia G D, Li Y X, et al. Asynchronous evolution of the isotopic composition and amount of precipitation in north China during the Holocene revealed by a record of compound-specific carbon and hydrogen isotopes of long-chain n-alkanes from an alpine lake [J]. Earth and Planetary Science Letters, 2016, 446: 68-76. doi: 10.1016/j.jpgl.2016.04.027
[24] Cheng H, Edwards R L, Sinha A, et al. The Asian monsoon over the past 640, 000 years and ice age terminations [J]. Nature, 2016, 534(7609): 640-646. doi: 10.1038/nature18591
[25] Cheng H, Zhang H W, Cai Y J, et al. Orbital-scale Asian summer monsoon variations: Paradox and exploration [J]. Science China Earth Sciences, 2021, 64(4): 529-544. doi: 10.1007/s11430-020-9720-y
[26] Zhang H W, Zhang X, Cai Y J, et al. A data-model comparison pinpoints Holocene spatiotemporal pattern of East Asian summer monsoon [J]. Quaternary Science Reviews, 2021, 261: 106911. doi: 10.1016/j.quascirev.2021.106911
[27] Beck J W, Zhou W J, Li C, et al. A 550, 000-year record of East Asian monsoon rainfall from 10Be in loess [J]. Science, 2018, 360(6391): 877-881. doi: 10.1126/science.aam5825
[28] Sun Y B, Kutzbach J, An Z S, et al. Astronomical and glacial forcing of East Asian summer monsoon variability [J]. Quaternary Science Reviews, 2015, 115: 132-142. doi: 10.1016/j.quascirev.2015.03.009
[29] Hao Q Z, Wang L, Oldfield F, et al. Delayed build-up of Arctic ice sheets during 400, 000-year minima in insolation variability [J]. Nature, 2012, 490(7420): 393-396. doi: 10.1038/nature11493
[30] Clemens S C, Holbourn A, Kubota Y, et al. Precession-band variance missing from East Asian monsoon runoff [J]. Nature Communications, 2018, 9(1): 3364. doi: 10.1038/s41467-018-05814-0
[31] Zhao D B, Wan S M, Lu Z Y, et al. Response of heterogeneous rainfall variability in East Asia to Hadley circulation reorganization during the late Quaternary [J]. Quaternary Science Reviews, 2020, 247: 106562. doi: 10.1016/j.quascirev.2020.106562
[32] Igarashi Y, Oba T. Fluctuations in the East Asian monsoon over the last 144ka in the northwest Pacific based on a high-resolution pollen analysis of IMAGES core MD01-2421 [J]. Quaternary Science Reviews, 2006, 25(13-14): 1447-1459. doi: 10.1016/j.quascirev.2005.11.011
[33] Morley J J, Heusser L E. Role of orbital forcing in East Asian monsoon climates during the last 350 kyr: evidence from terrestrial and marine climate proxies from core RC14‐99 [J]. Paleoceanography, 1997, 12(3): 483-493. doi: 10.1029/97PA00213
[34] Thomas E K, Clemens S C. Prell W L, et al. Temperature and leaf wax δ2H records demonstrate seasonal and regional controls on Asian monsoon proxies [J]. Geology, 2014, 42(12): 1075-1078. doi: 10.1130/G36289.1
[35] Kong X H, Zhou W J, Beck J W, et al. Loess magnetic susceptibility flux: a new proxy of East Asian monsoon precipitation [J]. Journal of Asian Earth Sciences, 2020, 201: 104489. doi: 10.1016/j.jseaes.2020.104489
[36] Sun Y B, Wang T, Yin Q Z, et al. A review of orbital-scale monsoon variability and dynamics in East Asia during the Quaternary [J]. Quaternary Science Reviews, 2022, 288: 107593. doi: 10.1016/j.quascirev.2022.107593
[37] Gu Z Y, Lal D, Liu T S, et al. Five million year 10Be record in Chinese loess and red-clay: climate and weathering relationships [J]. Earth and Planetary Science Letters, 1996, 144(1-2): 273-287. doi: 10.1016/0012-821X(96)00156-2
[38] Sun Y B, An Z S, Clemens S C, et al. Seven million years of wind and precipitation variability on the Chinese Loess Plateau [J]. Earth and Planetary Science Letters, 2010, 297(3-4): 525-535. doi: 10.1016/j.jpgl.2010.07.004
[39] Dai G W, Zhang Z S, Otterå O H, et al. A modeling study of the tripole pattern of East China precipitation over the past 425 ka [J]. Journal of Geophysical Research:Atmospheres, 2021, 126(7): e2020JD033513.
[40] 陈大可, 连涛. 厄尔尼诺-南方涛动研究新进展[J]. 科学通报, 2020, 65(35):4001-4003 doi: 10.1360/TB-2020-1219 CHEN Dake, LIAN Tao. Frontier of El Niño-Southern oscillation research [J]. Chinese Science Bulletin, 2020, 65(35): 4001-4003. doi: 10.1360/TB-2020-1219
[41] Hu D X, Wu L X, Cai W J, et al. Pacific western boundary currents and their roles in climate [J]. Nature, 2015, 522(7556): 299-308. doi: 10.1038/nature14504
[42] Navarra G G, Di Lorenzo E. Poleward shift and intensified variability of Kuroshio-Oyashio extension and North Pacific Transition Zone under climate change [J]. Climate Dynamics, 2021, 56(7-8): 2469-2486. doi: 10.1007/s00382-021-05677-0
[43] Wang L, Li T, Zhou T J. Intraseasonal SST variability and air-sea interaction over the Kuroshio Extension region during boreal summer [J]. Journal of Climate, 2012, 25(5): 1619-1634. doi: 10.1175/JCLI-D-11-00109.1
[44] Tittensor D P, Mora C, Jetz W, et al. Global patterns and predictors of marine biodiversity across taxa [J]. Nature, 2010, 466(7310): 1098-1101. doi: 10.1038/nature09329
[45] Noto M, Yasuda I. Population decline of the Japanese sardine, Sardinops melanostictus, in relation to sea surface temperature in the Kuroshio Extension [J]. Canadian Journal of Fisheries and Aquatic Sciences, 1999, 56(6): 973-983. doi: 10.1139/f99-028
[46] Zhang Y, Zhang Z G, Chen D K, et al. Strengthening of the Kuroshio current by intensifying tropical cyclones [J]. Science, 2020, 368(6494): 988-993. doi: 10.1126/science.aax5758
[47] Wu L X, Cai W J, Zhang L P, et al. Enhanced warming over the global subtropical western boundary currents [J]. Nature Climate Change, 2012, 2(3): 161-166. doi: 10.1038/NCLIMATE1353
[48] Vats N, Mishra S, Singh R K, et al. Paleoceanographic changes in the East China Sea during the last~400 kyr reconstructed using planktic foraminifera [J]. Global and Planetary Change, 2020, 189: 103173. doi: 10.1016/j.gloplacha.2020.103173
[49] Lam A R, Leckie R M. Subtropical to temperate late Neogene to Quaternary planktic foraminiferal biostratigraphy across the Kuroshio Current Extension, Shatsky Rise, northwest Pacific Ocean [J]. PLoS One, 2020, 15(7): e0234351. doi: 10.1371/journal.pone.0234351
[50] Gallagher S J, Kitamura A, Iryu Y, et al. The Pliocene to recent history of the Kuroshio and Tsushima Currents: a multi-proxy approach [J]. Progress in Earth and Planetary Science, 2015, 2(1): 17. doi: 10.1186/s40645-015-0045-6
[51] Gallagher S J, Wallace M W, Li C L, et al. Neogene history of the West Pacific Warm Pool, Kuroshio and Leeuwin currents [J]. Paleoceanography, 2009, 24(1): PA1206. doi: 10.1029/2008PA001660
[52] Lam A R, MacLeod K G, Schilling S H, et al. Pliocene to earliest pleistocene (5-2.5 Ma) reconstruction of the Kuroshio current extension reveals a dynamic current [J]. Paleoceanography and Paleoclimatology, 2021, 36(9): e2021PA004318. doi: 10.1029/2021PA004318
[53] LaRiviere J P, Ravelo A C, Crimmins A, et al. Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing [J]. Nature, 2012, 486(7401): 97-100. doi: 10.1038/nature11200
[54] Venti N L, Billups K, Herbert T D. Increased sensitivity of the Plio-Pleistocene northwest Pacific to obliquity forcing [J]. Earth and Planetary Science Letters, 2013, 384: 121-131. doi: 10.1016/j.jpgl.2013.10.007
[55] Rakestraw N W. The oceans: Their physics, chemistry, and general biology (Sverdrup, H. U.; Johnson, Martin W.; Fleming, Richard H.) [J]. Journal of Chemical Education, 1943, 20(10): 517. doi: 10.1021/ed020p517.1
[56] Talley L D. An Okhotsk Sea water anomaly: implications for ventilation in the North Pacific [J]. Deep Sea Research Part A. Oceanographic Research Papers, 1991, 38: S171-S190. doi: 10.1016/S0198-0149(12)80009-4
[57] Yasuda I, Kouketsu S, Katsumata K, et al. Influence of Okhotsk sea intermediate water on the Oyashio and North Pacific intermediate water [J]. Journal of Geophysical Research:Oceans, 2002, 107(C12): 3237. doi: 10.1029/2001JC001037
[58] You Y Z, Suginohara N, Fukasawa M, et al. Roles of the Okhotsk sea and gulf of alaska in forming the north pacific intermediate water [J]. Journal of Geophysical Research:Oceans, 2000, 105(C2): 3253-3280. doi: 10.1029/1999JC900304
[59] You Y Z. Implications of cabbeling on the formation and transformation mechanism of North Pacific Intermediate Water [J]. Journal of Geophysical Research:Oceans, 2003, 108(C5): 3134. doi: 10.1029/2001JC001285
[60] Talley L D. Distribution and formation of North Pacific intermediate water [J]. Journal of Physical Oceanography, 1993, 23(3): 517-537. doi: 10.1175/1520-0485(1993)023<0517:DAFONP>2.0.CO;2
[61] Sigman D M, Jaccard S L, Haug G H. Polar ocean stratification in a cold climate [J]. Nature, 2004, 428(6978): 59-63. doi: 10.1038/nature02357
[62] Haug G H, Sigman D M. Polar twins [J]. Nature Geoscience, 2009, 2(2): 91-92. doi: 10.1038/ngeo423
[63] Studer A S, Martínez-Garcia A, Jaccard S L, et al. Enhanced stratification and seasonality in the Subarctic Pacific upon Northern Hemisphere Glaciation-New evidence from diatom-bound nitrogen isotopes, alkenones and archaeal tetraethers [J]. Earth and Planetary Science Letters, 2012, 351-352: 84-94. doi: 10.1016/j.jpgl.2012.07.029
[64] Burls N J, Fedorov A V, Sigman D M, et al. Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene [J]. Science Advances, 2017, 3(9): e1700156. doi: 10.1126/sciadv.1700156
[65] Kender S, Ravelo A C, Worne S, et al. Closure of the Bering strait caused Mid-Pleistocene transition cooling [J]. Nature Communications, 2018, 9(1): 5386. doi: 10.1038/s41467-018-07828-0
[66] Cook M S, Ravelo A C, Mix A, et al. Tracing subarctic Pacific water masses with benthic foraminiferal stable isotopes during the LGM and late Pleistocene [J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2016, 125-126: 84-95. doi: 10.1016/j.dsr2.2016.02.006
[67] Sagawa T, Ikehara K. Intermediate water ventilation change in the subarctic northwest Pacific during the last deglaciation [J]. Geophysical Research Letters, 2008, 35(24): L24702. doi: 10.1029/2008GL035133
[68] Matsumoto K, Oba T, Lynch-Stieglitz J, et al. Interior hydrography and circulation of the glacial Pacific Ocean [J]. Quaternary Science Reviews, 2002, 21(14-15): 1693-1704. doi: 10.1016/s0277-3791(01)00142-1
[69] Keigwin L D. Glacial-age hydrography of the far northwest Pacific Ocean [J]. Paleoceanography, 1998, 13(4): 323-339. doi: 10.1029/98PA00874
[70] Keigwin L D. Late Pleistocene-Holocene paleoceanography and ventilation of the Gulf of California [J]. Journal of Oceanography, 2002, 58(2): 421-432. doi: 10.1023/A:1015830313175
[71] Ohkushi K, Itaki T, Nemoto N. Last Glacial-Holocene change in intermediate-water ventilation in the Northwestern Pacific [J]. Quaternary Science Reviews, 2003, 22(14): 1477-1484. doi: 10.1016/S0277-3791(03)00082-9
[72] Max L, Rippert N, Lembke-Jene L, et al. Evidence for enhanced convection of North Pacific Intermediate Water to the low-latitude Pacific under glacial conditions [J]. Paleoceanography, 2017, 32(1): 41-55. doi: 10.1002/2016PA002994
[73] Jang K, Huh Y, Han Y. Authigenic Nd isotope record of North Pacific Intermediate Water formation and boundary exchange on the Bering Slope [J]. Quaternary Science Reviews, 2017, 156: 150-163. doi: 10.1016/j.quascirev.2016.11.032
[74] Knudson K P, Ravelo A C. North Pacific intermediate water circulation enhanced by the closure of the Bering Strait [J]. Paleoceanography, 2015, 30(10): 1287-1304. doi: 10.1002/2015PA002840
[75] Lisiecki L E, Raymo M E. A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records [J]. Paleoceanography, 2005, 20(1): PA1003. doi: 10.1029/2004PA001071
[76] Bereiter B, Lüthi D, Siegrist M, et al. Mode change of millennial CO2 variability during the last glacial cycle associated with a bipolar marine carbon seesaw [J]. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(25): 9755-9760. doi: 10.1073/pnas.1204069109
[77] Rohling E J, Grant K, Bolshaw M, et al. Antarctic temperature and global sea level closely coupled over the past five glacial cycles [J]. Nature Geoscience, 2009, 2(7): 500-504. doi: 10.1038/ngeo557
[78] Sosdian S, Rosenthal Y. Deep-sea temperature and ice volume changes across the Pliocene-Pleistocene climate transitions [J]. Science, 2009, 325(5938): 306-310. doi: 10.1126/science.1169938
[79] Horikawa K, Kozaka Y, Okazaki Y, et al. Neodymium isotope records from the Northwestern Pacific: Implication for deepwater ventilation at Heinrich Stadial 1 [J]. Paleoceanography and Paleoclimatology, 2021, 36(10): e2021PA004312. doi: 10.1029/2021PA004312
[80] Okazaki Y, Timmermann A, Menviel L, et al. Deepwater formation in the North Pacific during the Last Glacial termination [J]. Science, 2010, 329(5988): 200-204. doi: 10.1126/science.1190612
[81] Kim S, Khim B K, Ikehara K, et al. Millennial-scale changes of surface and bottom water conditions in the northwestern Pacific during the last deglaciation [J]. Global and Planetary Change, 2017, 154: 33-43. doi: 10.1016/j.gloplacha.2017.04.009
[82] Detlef H, Sosdian S M, Belt S T, et al. Late quaternary sea-ice and sedimentary redox conditions in the eastern Bering Sea-implications for ventilation of the mid-depth North Pacific and an Atlantic-Pacific seesaw mechanism [J]. Quaternary Science Reviews, 2020, 248: 106549. doi: 10.1016/j.quascirev.2020.106549
[83] Rae J W B, Sarnthein M, Foster G L, et al. Deep water formation in the North Pacific and deglacial CO2 rise [J]. Paleoceanography, 2014, 29(6): 645-667. doi: 10.1002/2013PA002570
[84] Du J H, Haley B A, Mix A C, et al. Flushing of the deep Pacific Ocean and the deglacial rise of atmospheric CO2 concentrations [J]. Nature Geoscience, 2018, 11(10): 749-755. doi: 10.1038/s41561-018-0205-6
[85] Max L, Lembke-Jene L, Riethdorf J R, et al. Pulses of enhanced North Pacific Intermediate Water ventilation from the Okhotsk Sea and Bering Sea during the last deglaciation [J]. Climate of the Past, 2014, 10(2): 591-605. doi: 10.5194/cp-10-591-2014
[86] Jaccard S L, Galbraith E D. Direct ventilation of the North Pacific did not reach the deep ocean during the last deglaciation [J]. Geophysical Research Letters, 2013, 40(1): 199-203. doi: 10.1029/2012GL054118
[87] Ohkushi K, Hara N, Ikehara M, et al. Intensification of North Pacific intermediate water ventilation during the Younger Dryas [J]. Geo-Marine Letters, 2016, 36(5): 353-360. doi: 10.1007/s00367-016-0450-x
[88] Gong X, Lembke-Jene L, Lohmann G, et al. Enhanced North Pacific deep-ocean stratification by stronger intermediate water formation during Heinrich Stadial 1 [J]. Nature Communications, 2019, 10(1): 656. doi: 10.1038/s41467-019-08606-2
[89] Talley L D. Closure of the global overturning circulation through the Indian, Pacific, and Southern Oceans: Schematics and transports [J]. Oceanography, 2013, 26(1): 80-97. doi: 10.5670/oceanog.2013.07
[90] Houghton R A. Balancing the global carbon budget [J]. Annual Review of Earth and Planetary Sciences, 2007, 35: 313-347. doi: 10.1146/annurev.earth.35.031306.140057
[91] Zeebe R E. History of seawater carbonate chemistry, atmospheric CO2, and ocean acidification [J]. Annual Review of Earth and Planetary Sciences, 2012, 40: 141-165. doi: 10.1146/annurev-earth-042711-105521
[92] Jacobel A W, Anderson R F, Jaccard S L, et al. Deep Pacific storage of respired carbon during the last ice age: perspectives from bottom water oxygen reconstructions [J]. Quaternary Science Reviews, 2020, 230: 106065. doi: 10.1016/j.quascirev.2019.106065
[93] Jaccard S L, Galbraith E D, Sigman D M, et al. Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool [J]. Earth and Planetary Science Letters, 2009, 277(1-2): 156-165. doi: 10.1016/j.jpgl.2008.10.017
[94] Hu R, Piotrowski A M. Neodymium isotope evidence for glacial-interglacial variability of deepwater transit time in the Pacific Ocean [J]. Nature Communications, 2018, 9(1): 4709. doi: 10.1038/s41467-018-07079-z
[95] Wan S, Jian Z M, Gong X, et al. Deep water[CO32−] and circulation in the south China sea over the last glacial cycle [J]. Quaternary Science Reviews, 2020, 243: 106499. doi: 10.1016/j.quascirev.2020.106499
[96] de la Fuente M, Skinner L, Calvo E, et al. Increased reservoir ages and poorly ventilated deep waters inferred in the glacial Eastern Equatorial Pacific [J]. Nature Communications, 2015, 6: 7420. doi: 10.1038/ncomms8420
[97] Skinner L C, Primeau F, Freeman E, et al. Radiocarbon constraints on the glacial ocean circulation and its impact on atmospheric CO2 [J]. Nature Communications, 2017, 8: 16010. doi: 10.1038/ncomms16010
[98] Yu J M, Anderson R F, Jin Z D, et al. Responses of the deep ocean carbonate system to carbon reorganization during the Last Glacial-interglacial cycle [J]. Quaternary Science Reviews, 2013, 76: 39-52. doi: 10.1016/j.quascirev.2013.06.020
[99] Jaccard S L, Galbraith E D. Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation [J]. Nature Geoscience, 2012, 5(2): 151-156. doi: 10.1038/ngeo1352
[100] Lund D C. Deep Pacific ventilation ages during the last deglaciation: Evaluating the influence of diffusive mixing and source region reservoir age [J]. Earth and Planetary Science Letters, 2013, 381: 52-62. doi: 10.1016/j.jpgl.2013.08.032
[101] Lund D C, Mix A C, Southon J. Increased ventilation age of the deep northeast Pacific Ocean during the last deglaciation [J]. Nature Geoscience, 2011, 4(11): 771-774. doi: 10.1038/ngeo1272
[102] Janecek T R, Rea D K. Eolian deposition in the northeast Pacific Ocean: Cenozoic history of atmospheric circulation [J]. Geological Society of America Bulletin, 1983, 94(6): 730-738. doi: 10.1130/0016-7606(1983)94<730:EDITNP>2.0.CO;2
[103] Janecek T R. Eolian sedimentation in the northwest Pacific Ocean: A preliminary examination of the data from Deep Sea Drilling Project sites 576 and 578[R]. Initial Reports, DSDP, 86, 1985: 589-603. doi: 10.2973/dsdp.proc.86.126.1985.
[104] Anderson C H, Murray R W, Dunlea A G, et al. Aeolian delivery to Ulleung Basin, Korea (Japan Sea), during development of the East Asian Monsoon through the last 12 Ma [J]. Geological Magazine, 2020, 157(5): 806-817. doi: 10.1017/S001675681900013X
[105] Zhang W F, Chen J, Ji J F, et al. Evolving flux of Asian dust in the North Pacific Ocean since the late Oligocene [J]. Aeolian Research, 2016, 23: 11-20. doi: 10.1016/j.aeolia.2016.09.004
[106] Rea D K, Snoeckx H, Joseph L H. Late Cenozoic Eolian deposition in the North Pacific: Asian drying, Tibetan uplift, and cooling of the northern hemisphere [J]. Paleoceanography, 1998, 13(3): 215-224. doi: 10.1029/98PA00123
[107] Jiang X D, Zhao X, Zhao X Y, et al. Abyssal manganese nodule recording of global cooling and Tibetan Plateau uplift impacts on Asian aridification [J]. Geophysical Research Letters, 2022, 49(3): e2021GL096624. doi: 10.1029/2021GL096624
[108] Zhang Q, Liu Q S, Roberts A P, et al. Mechanism for enhanced eolian dust flux recorded in North Pacific Ocean sediments since 4.0 Ma: aridity or humidity at dust source areas in the Asian interior? [J]. Geology, 2020, 48(1): 77-81. doi: 10.1130/G46862.1
[109] Shi Z G, Liu X D, An Z S, et al. Simulated variations of eolian dust from inner Asian deserts at the mid-Pliocene, last glacial maximum, and present day: contributions from the regional tectonic uplift and global climate change [J]. Climate Dynamics, 2011, 37(11-12): 2289-2301. doi: 10.1007/s00382-011-1078-1
[110] Abell J T, Winckler G, Anderson R F, et al. Poleward and weakened westerlies during Pliocene warmth [J]. Nature, 2021, 589(7840): 70-75. doi: 10.1038/s41586-020-03062-1
[111] Serno S, Winckler G, Anderson R F, et al. Change in dust seasonality as the primary driver for orbital-scale dust storm variability in East Asia [J]. Geophysical Research Letters, 2017, 44(8): 3796-3805. doi: 10.1002/2016GL072345
[112] Zhang W F, Li G J, Chen J. The application of Neodymium isotope as a chronostratigraphic tool in North Pacific sediments [J]. Geological Magazine, 2020, 157(5): 768-776. doi: 10.1017/S001675681900089X
[113] McGee D, Broecker W S, Winckler G. Gustiness: the driver of glacial dustiness? [J]. Quaternary Science Reviews, 2010, 29(17-18): 2340-2350. doi: 10.1016/j.quascirev.2010.06.009
[114] Nagashima K, Tada R, Tani A, et al. Millennial-scale oscillations of the westerly jet path during the last glacial period [J]. Journal of Asian Earth Sciences, 2011, 40(6): 1214-1220. doi: 10.1016/j.jseaes.2010.08.010
[115] Luetscher M, Boch R, Sodemann H, et al. North Atlantic storm track changes during the Last Glacial Maximum recorded by Alpine speleothems [J]. Nature Communications, 2015, 6: 6344. doi: 10.1038/ncomms7344
[116] Vandenberghe J, Renssen H, van Huissteden K, et al. Penetration of Atlantic westerly winds into Central and East Asia [J]. Quaternary Science Reviews, 2006, 25(17-18): 2380-2389. doi: 10.1016/j.quascirev.2006.02.017
[117] Broecker W S. Glacial to interglacial changes in ocean chemistry [J]. Progress in Oceanography, 1982, 11(2): 151-197. doi: 10.1016/0079-6611(82)90007-6
[118] Broecker W S. Ocean chemistry during glacial time [J]. Geochimica et Cosmochimica Acta, 1982, 46(10): 1689-1705. doi: 10.1016/0016-7037(82)90110-7
[119] Harada N, Sato M, Shiraishi A, et al. Characteristics of alkenone distributions in suspended and sinking particles in the northwestern North Pacific [J]. Geochimica et Cosmochimica Acta, 2006, 70(8): 2045-2062. doi: 10.1016/j.gca.2006.01.024
[120] Takahashi T, Sutherland S C, Wanninkhof R, et al. Climatological mean and decadal change in surface ocean pCO2, and net sea-air CO2 flux over the global oceans [J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2009, 56(8-10): 554-577. doi: 10.1016/j.dsr2.2008.12.009
[121] Rae J W B, Gray W R, Wills R C J, et al. Overturning circulation, nutrient limitation, and warming in the Glacial North Pacific [J]. Science Advances, 2020, 6(50): eabd1654. doi: 10.1126/sciadv.abd1654
[122] Haug G H, Sigman D M, Tiedemann R, et al. Onset of permanent stratification in the subarctic Pacific Ocean [J]. Nature, 1999, 401(6755): 779-782. doi: 10.1038/44550
[123] Snoeckx H D, Rea D K, Jones C E, et al. Aeolian and silica deposition in the central North Pacific: Results from sites 885/886 [R]. Scientific Results, ODP, 145, 1995: 219-230, doi: 10.2973/odp.proc.sr.145.123.1995.
[124] Iwasaki S, Takahashi K, Kanematsu Y, et al. Paleoproductivity and paleoceanography of the last 4.3 Myrs at IODP Expedition 323 Site U1341 in the Bering Sea based on biogenic opal content [J]. Deep Sea Research Part Ⅱ:Tropical Studies in Oceanography, 2016, 125-126: 145-154. doi: 10.1016/j.dsr2.2015.04.005
[125] Stroynowski Z, Ravelo A C, Andreasen D. A Pliocene to recent history of the Bering Sea at Site U1340A, IODP Expedition 323 [J]. Paleoceanography, 2015, 30(12): 1641-1656. doi: 10.1002/2015PA002866
[126] Jaccard S L, Galbraith E D, Sigman D M, et al. A pervasive link between Antarctic ice core and subarctic Pacific sediment records over the past 800 kyrs [J]. Quaternary Science Reviews, 2010, 29(1-2): 206-212. doi: 10.1016/j.quascirev.2009.10.007
[127] Knudson K P, Ravelo A C. Enhanced subarctic Pacific stratification and nutrient utilization during glacials over the last 1.2Myr [J]. Geophysical Research Letters, 2015, 42(22): 9870-9879. doi: 10.1002/2015GL066317
[128] Maeda L, Kawahata H, Nohara M. Fluctuation of biogenic and abiogenic sedimentation on the Shatsky Rise in the western north Pacific during the late Quaternary [J]. Marine Geology, 2002, 189(3-4): 197-214. doi: 10.1016/S0025-3227(02)00405-X
[129] Amo M, Minagawa M. Sedimentary record of marine and terrigenous organic matter delivery to the Shatsky Rise, western North Pacific, over the last 130 kyr [J]. Organic Geochemistry, 2003, 34(9): 1299-1312. doi: 10.1016/S0146-6380(03)00113-X
[130] Burgay F, Spolaor A, Gabrieli J, et al. Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean [J]. Climate of the Past, 2021, 17(1): 491-505. doi: 10.5194/cp-17-491-2021
[131] Moore C M, Mills M M, Arrigo K R, et al. Processes and patterns of oceanic nutrient limitation [J]. Nature Geoscience, 2013, 6(9): 701-710. doi: 10.1038/ngeo1765
[132] Knudson K P, Ravelo A C, Aiello I W, et al. Causes and timing of recurring subarctic Pacific hypoxia [J]. Science Advances, 2021, 7(23): eabg2906. doi: 10.1126/sciadv.abg2906
[133] Han Y X, Zhao T L, Song L C, et al. A linkage between Asian dust, dissolved iron and marine export production in the deep ocean [J]. Atmospheric Environment, 2011, 45(25): 4291-4298. doi: 10.1016/j.atmosenv.2011.04.078
[134] Müller J, Romero O, Cowan E A, et al. Cordilleran ice-sheet growth fueled primary productivity in the Gulf of Alaska, northeast Pacific Ocean [J]. Geology, 2018, 46(4): 307-310. doi: 10.1130/g39904.1
[135] Kim S, Takahashi K, Khim B K, et al. Biogenic opal production changes during the Mid-Pleistocene Transition in the Bering Sea (IODP Expedition 323 Site U1343) [J]. Quaternary Research, 2014, 81(1): 151-157. doi: 10.1016/j.yqres.2013.10.001
[136] Jaccard S L, Hayes C T, Martínez-García A, et al. Two modes of change in southern ocean productivity over the past million years [J]. Science, 2013, 339(6126): 1419-1423. doi: 10.1126/science.1227545
[137] Weber M E, Bailey I, Hemming S R, et al. Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years [J]. Nature Communications, 2022, 13(1): 2044. doi: 10.1038/s41467-022-29642-5
[138] Koffman B G, Yoder M F, Methven T, et al. Glacial dust surpasses both volcanic ash and desert dust in its iron fertilization potential [J]. Global Biogeochemical Cycles, 2021, 35(4): e2020GB006821. doi: 10.1029/2020GB006821
[139] Walczak M H, Mix A C, Cowan E A, et al. Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans [J]. Science, 2020, 370(6517): 716-720. doi: 10.1126/science.aba7096
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