Using uranium-series radionuclides as tools for tracing marine sedimentary processes: Source identification, sedimentation rate, and sediment resuspension
-
摘要: 放射性核素示踪技术被广泛应用于海洋学研究。海洋沉积物是许多物质的归宿，海洋沉积过程的研究常关注3个关联问题：物质来源、沉积速率、再悬浮过程。针对这3个问题，在南海9个珊瑚礁区、北部湾涠洲岛海域、珠江口、北冰洋、南大洋等多个海区利用典型的铀系放射性核素（210Pb、226Ra、234Th、238U）示踪技术开展海洋沉积过程研究。物源识别方面，研究发现珊瑚礁区沉积物具有极低的226Ra/238U活度比值（＜0.1），显著低于其他海区的226Ra/238U活度比值（0.5～1.0），该独特性质可以应用于珊瑚礁区的沉积物/悬浮物来源示踪，是其他传统元素地球化学方法（Al、Ti、稀土元素）的补充。沉积速率方面，基于210Pb的恒定通量恒定沉积速率（Constant Flux Constant Sedimentation Model, CFCS）模式，定量计算了广西涠洲岛珊瑚礁区沉积柱样的沉积速率（3.7±0.6 mm/a），该结果低于中国多个近岸海域的沉积速率（5～96 mm/a）。沉积物再悬浮方面，提出利用“残余234Th”（不同于过剩234Th）示踪海洋沉积物再悬浮过程，并成功应用于北冰洋、南海、南大洋。Abstract: Radionuclides are widely used as tracers in oceanography. As the final fate of many substances, marine sediment is mainly concerned from three perspectives: source identification, sedimentation rate, and sediment resuspension. In the present study, uranium-series radionuclides (210Pb, 226Ra, 234Th, and 238U) are applied in several sea regions such as the nine typical coral reefs in the South China Sea, the Weizhou Island, the Pearl River Estuary, the Arctic Ocean, and the Southern Ocean, to study the sediment source, sedimentation rate, and sediment resuspension. Firstly, activity ratio of 226Ra to 238U was found extremely low (＜0.1) in the marine sediment of coral reef regions comparing to the activity ratios (0.5～1.0) in other marine sediments and therefore, it could be used as the tool to identify the sources of marine sediments from coral reef regions in addition to other geochemical tools (Al, Ti, and REE). Secondly, the sedimentation rate (3.7±0.6 mm/a) was calculated for a sediment core taking from the coral reefs near the Weizhou Island via excess 210Pb (Constant Flux Constant Sedimentation Model, CFCS model in brief) which was lower than most figures (5 mm/a～96 mm/a) in other coastal areas of China. Finally, residual β activity of particulate 234Th (RAP234) was proposed for tracking marine sediment resuspension. The RAP234 was successfully applied in the Arctic Ocean, South China Sea, and Southern Ocean. In conclusion, the successful applications of these radioactive tracers have provided potential tools used for tracing marine sedimentary processes in addition to the ongoing toolbox.
-
Keywords:
- radionuclides /
- sediment /
- tracer /
- coral reefs /
- residual β activity of particulate 234Th
-
海底峡谷通常发育在陆架陆坡区，是陆源物质向深海运移的重要通道[1]。海底峡谷既可发育于主动大陆边缘，又可发育于被动大陆边缘[2]。浊流通常被认为是峡谷内部物质输运的主要营力，尤其对于那些与陆地河流连接的峡谷。Xu等监测到蒙特利峡谷最大的浊流速度可达2.60 m/s[3]；Paull等推算的浊流的前锋可以达到7.2 m/s，并且浊流能够以至少4 m/s的速度搬运800 kg的物体[4]。2006年台湾西南恒春地震引起了多处的滑坡和浊流，有序切断了1 500～4 000 m水深的14条电缆，其中6条在峡谷外，估算的流速为3.7～20 m/s[5]。同样的事情发生在2009年，莫拉克台风引起的高密度流/浊流有序切断了多条海底通讯电缆，计算的最大速度达16.6 m/s[6]。
南海神狐峡谷群是垂直陆坡方向发育的多条近似平行的限制型海底峡谷（图1a、b）。神狐峡谷群远离陆地，更新世以来沉积速率较高（20～34.16 cm/ka）[7]，海底发育了总面积超过1 000 km2的滑动、滑塌、碎屑流等块体搬运沉积（MTDs, Mass Transport Deposits）[8-9]。与同处南海北部陆缘且有大量碎屑物质输入的台湾高屏海底峡谷相比，陆坡限定性峡谷内浊流发生的频率相对较小[5]。
![]()
图 1 研究区位置a.神狐峡谷群的位置，b.神狐峡谷群海底地形图，c.基于三维地震资料的研究区海底地形图，d.基于AUV采集的多波束的研究区海底地形图。Figure 1. Locations of the study areaa. The location of the studied slope confined canyons, b. the bathymetric map of canyons, c. the bathymetric map of the studied canyon segment based on 3D seismic reflection data, d. the bathymetric map of the studied canyon segment based on multi-beam data acquired by AUV.以往对深水区地层结构的探测主要依赖二维、三维（2D/3D）反射地震资料和浅地层剖面；前者探测深度几千米，分辨率较低，在数米至数十米之间；后者探测深度较浅，几十米到几百米，容易受到能量吸收和复杂作业环境干扰，设备分辨率较高，但实际获取的数据质量较差。即便是能量和探测精度更高的电火花震源，其分辨率也只有约2 m。这对于研究深水区海底沉积层的精细结构是不够的。AUV探测是加载各种探测设备的自主水下航行器保持与海底几十米的距离并按照设定的路由线路进行数据采集，具有很好的横向和纵向的分辨率，例如中海油服3 000 m级AUV携带的EdgeTech2200-M浅剖仪的垂向分辨率可达6～10 cm[10-11]。国际上AUV探测已经越来越多地应用到深海沉积研究中[12-14]。国内也研发出多套AUV设备，但应用范围有限[15]。
对于神狐峡谷群，以往的研究主要集中在滑坡广泛发育的崎岖的峡谷脊部，但对较为平坦的峡谷谷底研究较少。本文利用AUV获取的地球物理资料刻画神狐峡谷谷底沉积特征，对研究陆坡限定性峡谷的物质输运过程具有重要意义。
1. 地质概况
神狐峡谷群分布在珠江口外海陆坡区，具体位于珠江口盆地的白云凹陷。珠江口盆地所在的南海北部经历古近纪的裂陷期和新近纪―第四纪的裂后期[16]。在约23.8 Ma的渐新世末期，受南海扩张中心南向跃迁的影响，陆架坡折带从白云凹陷的南部退移到目前的位置[17]。神狐峡谷群开始于13.8 Ma的中中新世，经历了4个期次的北东向迁移发育，峡谷覆盖面积从Ⅰ期（13.8～12.5 Ma）、Ⅱ期（12.5～10.5 Ma）到Ⅲ期（10.5～5.5 Ma）逐渐增大，再到Ⅳ期（1.8 Ma～）缩小[18-19]。浊流、底流及两者之间的相互作用被认为影响了峡谷的迁移发育[20-22]。
2. 数据和方法
研究使用了三维地震数据和AUV资料进行对比分析。三维地震数据的时间采样间隔2～4 ms，空间采样间隔6.25 m×12.5 m，上部1 500 m地层主频约为40 Hz。三维地震数据中的海底反射时间经时深转换生成水深图（海水声速取值1 500 m/s）。AUV资料使用Echo Surveyor III（Kongsberg Hugin 1000 AUV）采集，主要加载了多波束、旁扫声呐和浅地层剖面仪等设备。多波束为Kongsberg EM2000，声脉冲频率平均2 Hz，扫描宽度为240 m，水平分辨率可以达到0.6 m；旁扫声呐用来反映地形变化和底质类型，采用Edgetech全谱旁扫声呐，频率105/410 kHz，声脉冲频率3 Hz，脉冲长度9 ms/2 ms，扫描范围221 m/100 m；浅地层剖面仪为Edgetech全谱线性调频剖面仪，频率范围2～16 kHz，实际工作频率2～10 kHz，地层分辨率可达3～4 cm，声脉冲频率3 Hz，记录长度143 ms。作业时AUV在距海底35 m的水深处以3～4节的速度航行。2010年在水深1 302.21 m的块体搬运沉积体上实施了重力柱状取样（GC-3），取样长度3.6 m。基于AUV获取的旁扫声呐、浅地层剖面和多波束等高分辨率地球物理数据，对第14条峡谷进行了海底地貌和部分谷底的浅地层分析。
3. 结果
3.1 峡谷地形地貌特征
神狐峡谷群水深200～2 000 m，由19条近似平行的峡谷组成。峡谷起源于陆坡的上部，向深水逐渐加宽，最下端汇聚到珠江大峡谷。峡谷长3.6～36 km，宽1～5 km，深100～400 m。峡谷脊部地形崎岖不平，沟壑陡崖普遍发育，峡谷谷底较为平坦（图1）。基于三维反射地震可以在峡谷谷底观测到巨大的陡崖和大型的沟槽，可以大体分辨边界明显的MTDs（图1c）。基于AUV获取的旁扫声呐图则更加清晰地展示了所选取峡谷谷底的精细地貌特征（图1b，图2a）。MTDs在谷底广泛分布，总面积近17 km2。MTDs在峡谷头部的弧形斜坡和谷底都有分布，MTDs呈不规则的圆形展布，其表面起伏不平（图2b）；在峡谷中下游MTDs沿着谷底狭长条带状分布（图2c-e）。基于AUV的多波束数据（图1d）和旁扫声呐数据（图2d），选取了峡谷下游水深1 280～1 360 m、距离峡谷出口10～15 km的 MTDs典型发育区进行了详细分析。3个MTDs分别位于不同台阶上（图3，图4）。MTDs的上面发育了数量众多的宽3～10 m、长20～700 m、深5～20 cm的冲蚀沟槽（图3）。MTDs的厚度都在8.4 m及以下，这在常规2D/3D地震资料上是难以分辨的（图4）。
![]()
图 2 峡谷的旁扫声呐图和岩心图a.研究区所在峡谷的旁扫声呐图，b—e.局部放大的旁扫声呐图，f—g. MTD1上GC-3站位的部分重力柱状岩心样品。虚线多边形指示MTDs的位置。Figure 2. The side-scan sonar map of the canyon floor and sections of the gravity core acquired from the canyon floora. The side-scan sonar map of the studied canyon, b-e. amplified side-scan sonar maps of the study area, f-g. sediment samples from the gravity core GC-3 over MTD1 at 1.25 m and 3.25 m, respectively. The dashed polygons denote locations of MTDs on the canyon floor.![]()
图 3 研究区3个典型MTDs的地形立体图及穿过MTDs的地形变化曲线Figure 3. Stereo views of three MTDs and bathymetric curves crossing these MTDs![]()
图 4 过同一峡谷位置的三维反射地震剖面和AUV浅地层剖面a.反射地震剖面，b.AUV浅地层剖面。Figure 4. The seismic profile exttracted from the 3D seismic data and sub-bottom profiles acquired by AUV crossing the same section of the canyona. The seismic profile, b. The AUV based sub-bottom profile.3.2 MTD1
MTD1位于谷底的最西边，是峡谷谷底主水道的位置，中间宽、上下两端窄，在下部受到突出的水道堤岸的阻挡而改变方向且宽度变窄。MTD1的上部可以识别出狭长的渠道状的物质输运后的残留物（图3），而在MTD1邻近的峡谷翼部没有识别出明显的滑坡体或滑坡遗迹。MTD1长5.00 km，头尾两端厚度小，中间厚度大，厚度最小1.30 m，最大8.40 m，面积 0.90 km2，体积约4.37 km3（表1）。MTD1可以清晰识别出连续的底边界反射指示底部剪切面，其反射强度低于海底反射但明显高于其他正常地层反射。MTD1内部为振幅较弱的杂乱反射（图5），仅在底部的局部位置有少量的长度有限的连续反射轴（图5c）。沉积体上发育了大量平直的冲蚀沟槽，尤其在主水道上更为低洼的地方（图3）。基于AUV的旁扫声呐图（浅色）指示整条峡谷谷底浅表层主要由软的沉积物组成（图2）；重力柱状取样结果证实MTD1沉积体由很软的高可塑性的灰绿色粉砂组成，含非常少的砂（图2f—g）。
表 1 峡谷谷底MTDs的几何参数Table 1. Geometric parameters of MTDs on the canyon floor编号 宽度/m 长度/km 长宽比 厚度/m 面积/km2 体积/km3 MTD1 80～500 5.00 10.00～62.50 1.30～8.40 0.90 4.37 MTD2 260～350 0.75 2.14～2.88 0.90～3.20 0.28 0.58 MTD3 70～600 2.00 3.33～28.57 1.20～3.00 1.10 2.31 ![]()
图 5 过MTD1的AUV浅地层剖面图a.上部横剖面，b.中部横剖面，c.下部横剖面。Figure 5. AUV based sub-bottom profiles across MTD1a. The upper profile perpendicular to the strike, b. the middle profile perpendicular to the strike, c. the lower profile perpendicular to the strike.3.3 MTD2
MTD2位于峡谷谷底中部的台阶上，平面上呈不规则梯形展布（图1d，图2d，图3）。MTD2并非直接出露在海底，上部覆盖了一层厚约0.6 m的沉积层。MTD2宽度变化不大，为260.0～350.0 m；长750.0 m；厚0.90～3.20 m；面积较小，为0.28 km2；体积约0.58 km3 （表1）。MTD2沉积体上面也发育有冲蚀沟槽，此外在沉积体头部发育了更多的冲沟。MTD2同样可以识别出强反射的底边界和弱的顶界面。底边界并非平直光滑，而是出现了大量的凹槽，这些凹槽宽5.0～20.0 m，高0.375～0.75 m，其宽度明显大于沉积体上面的冲蚀沟槽，推测是由块体搬运沉积体在运动过程中侵蚀海底形成的侵蚀沟。不同于MTD1两端较小的厚度，MTD2从头部到尾部厚度逐渐减小（图6）。
![]()
图 6 过MTD2的AUV浅地层剖面图a.横剖面，b.纵剖面。Figure 6. AUV based sub-bottom profiles across MTD2a. The profile perpendicular to the strike, b. the profile parallel to the strike.3.4 MTD3
MTD3位于谷底最东侧的台阶上。头部宽度小，中部和尾部宽度大。MTD3长2.0 km，宽70～600 m，厚1.2～3.0 m，面积1.10 km2，体积约2.31 km3。垂直于峡谷走向，沉积体呈楔形展布，整个沉积体分布在中间低两侧高的大型凹槽中（图3，图7a—b）。MTD3在大型凹槽东侧宽度大于其西侧宽度，且东侧厚度逐渐变薄。沿着峡谷走向，沉积体厚度在中部最大，头部稍小，尾部最薄。MTD3底部反射较为平滑，反射强度较强，但明显小于MTD1和MTD2的底部反射强度。
![]()
图 7 过MTD3的AUV浅地层剖面图a.上部横剖面，b.下部横剖面，c.纵剖面。Figure 7. AUV based sub-bottom profiles across MTD3a. The upper profile perpendicular to the strike, b. the lower profile perpendicular to the strike, c. the profile parallel to the strike.4. 讨论
4.1 峡谷谷底MTDs的形成
通过对MTDs埋深的分析，推断MTDs形成的时间距今不远，因为在MTD1和MTD3上面没有识别出正常沉积的地层。MTD2的上部发育厚约0.60 m的沉积地层（图6），明显晚于MTD1和MTD2。
基于AUV的地球物理资料对MTDs特征的分析结果，我们推测峡谷中下游大多数MTDs并不是直接从邻近的峡谷脊部上搬运下来，而是从上游通过滑塌-碎屑流的形式运移下来。首先，除了峡谷头部弧形斜坡分布有大量不规则圆形展布的MTDs，峡谷中下游的MTDs大都沿峡谷走向狭长展布，并不是垂直峡谷走向展布（图2）。虽然脊部沉积物滑移后可以继续通过谷底向下继续运移，但在谷底两侧靠近坡脚的位置并没有发现较厚块体搬运沉积体的存在，在邻近的脊部也没有发现物质滑移的证据，相反，我们在MTD1上部发现了明显的物质输运后的残留遗迹（图5a）。MTD2具有较小的长宽比以及逐渐减小的厚度，说明该沉积体搬运的距离并不远（表1，图6），推测其是从邻近的谷底陡坡上搬运下来。MTD3 沉积体在大型凹槽东侧宽度要大于西侧，且东侧的沉积厚度向东逐渐变薄，说明MTD3不是直接来源于峡谷东侧的脊部，这表明峡谷上游比中下游发生滑坡的概率更大。三维反射地震资料的解释也表明MTDs在峡谷上游的数量更多，分布面积更广（图2a）[8-9]。虽然三维反射地震资料也显示峡谷中下游的脊部有大量MTDs，但这些MTDs厚度较大，在几十米以上，很多MTDs的内部地层变形不严重，反映了块体滑移或程度较弱的滑塌，但不能反映当前较小时间尺度内峡谷谷底的沉积过程。相比较而言，基于AUV的高分辨地球物理资料更真实反映了峡谷内部的沉积特征和过程，即当前或较短时间内峡谷谷底分布着大量小规模的沿峡谷走向呈狭长展布的MTDs。
研究区声学剖面上的块体搬运沉积体可能是一次块体流沉积的结果，也可能是多次块体流沉积的结果，但块体流间隔的时间较短，没有形成声学可识别的正常沉积地层。MTD1所处的谷底主水道位置更容易汇聚长距离搬运下来的碎屑流沉积。
4.2 峡谷谷底的物质输运
神狐峡谷群距离陆地近250 km，河流高悬浮物注入引起的浊流对峡谷影响很小，在MTD1上GC-3站位细粒粉砂沉积物也指示缺少陆源粗粒沉积物的输入。前人的研究表明峡谷坡度较陡的脊部发育了大量的MTDs，形成了起伏不平的地貌[23]，谷底地形相对比较平坦。通过以上对AUV获取的高分辨率地形和浅部地层资料的解析，我们认识到峡谷谷底并不像它的地表那么简单，而是在平坦的地表下发育了MTDs。这些MTDs的面积和厚度远没有峡谷脊部的大，但在峡谷谷底大量分布。峡谷中下游谷底的大多数MTDs并不是直接来源于峡谷脊部，而是来自MTDs的上部。这指示了峡谷谷底的物质输送的一种重要途径可能是通过不断重复的发生块体搬运沉积的形式进行的。滑坡并引起浊流被认为是陆坡限定性峡谷物质输运的主要营力，这种情况下浊流的产生通常是伴随着滑塌-碎屑流的产生而产生。在高海平面的情况下，以紊流为支撑力的浊流会侵蚀并携带部分沉积物流向下坡方向输运，但很难将垂直峡谷走向的MTDs完全改造成沿峡谷走向展布而不留下痕迹，除非发生大规模的滑坡事件。但高分辨率AUV资料表明目前的峡谷中下游的谷底只是分布着大量的小规模MTDs，而不是大量的浊流沉积体。据此，我们认为AUV可辨识的较小的时间尺度范围内，在特定沉积环境下（比如高海平面时期），神狐峡谷内物质输运的主要营力不只是浊流，还应该考虑峡谷谷底不断重复进行的块体搬运沉积过程。AUV资料和三维反射地震资料的解释结果并不冲突，只是存在空间尺度和时间尺度的不同。新形成的MTDs的表面通常会有沉积物堆积造成的凹凸不平，但谷底MTDs的表面只发育了大量小型冲蚀沟槽，这很可能是峡谷内部的较强的水动力对MTDs表面进行了改造。前人研究表明，神狐峡谷内部具有复杂的海洋水动力环境，其中内潮普遍发育且能量最大，峡谷内部发育的内潮最大流速可达50 cm/s，沿着峡谷轴向往复运动[24]。MTDs沉积体上面的冲沟是由潮流、余流还是其他类型的水体运动造成的还不明确。
5. 结论
（1）基于AUV的高分辨率多波束，旁扫声呐和浅地层剖面数据对峡谷整体和局部的MTDs进行了精细刻画，在峡谷谷底识别了常规地球物理资料不能辨识或不能清晰辨识的大量MTDs的分布。峡谷上游弧形斜坡和谷底分布着大量不规则圆形展布的MTDs，峡谷中下游的MTDs多在谷底呈狭长展布。
（2）对MTDs典型发育区的研究表明，MTDs沉积体的厚度在8.4 m及以下，沉积体内部为反射强度较弱的杂乱反射，推断为经过一定搬运距离而充分混合的碎屑流。
（3）通过分析MTDs沉积体的形态、沉积厚度变化并结合谷底两侧峡谷脊部的地层反射特征，认为谷底分布的MTDs主要来源于其上部，而不是邻近的峡谷脊部。在特定沉积环境和较小时间尺度范围内，除了浊流外，从峡谷上游到下游的块体搬运沉积过程的重复发生很可能是峡谷物质输运的另一种重要形式。
-
![]()
图 1 放射性核素示踪技术在海洋过程研究中的典型应用
Figure 1. Typical application of radionuclides to tracing marine processes
![]()
图 2 海洋沉积物采样站位分布和对应的沉积物中226Ra和238U活度
k值代表226Ra/238U的活度比值。绿色椭圆表示环礁的226Ra/238U活度比值（＜0.1）。长方形代表岸礁的沉积物226Ra/238U活度比值。紫色椭圆代表其他海区的沉积物226Ra/238U的活度比值（0.5～1）。
Figure 2. Sampling station map of China for marine sediments and their associated 226Ra and 238U activities
k means activity ratio of 226Ra to 238U. The green ellipse indicates marine sediments from the atoll reefs with k values ＜0.1. The black rectangle shows marine sediments from the fringing reefs. The purple ellipse represents marine sediments excluding coral reefs with k values of 0.5～1.0.
![]()
图 3 广西涠洲岛珊瑚礁区沉积物柱状样的站位图与过剩210Pb活度自然对数计算后的垂直分布
Figure 3. Location map of the sediment core collected from the Weizhou Island, Guangxi Province and vertical profile of excess 210Pb activity with Napierian Logarithm transformation
![]()
图 4 北冰洋陆架区（a）、南海珠江口陆架区（b）、南大洋陆架区（c）不同站位的残余234Th（RAP234）剖面图
黄色椭圆形代表沉积物再悬浮过程引起RAP234异常高值。
Figure 4. Vertical profiles of RAP234 in Arctic Ocean （a）, South China Sea （b）, and Southern Ocean （c）
Abnormal high RAP234 activity is indicated by yellow ellipses.
![]()
图 5 北冰洋SR3站位的海水浊度与残余234Th剖面图对比
Figure 5. Vertical profies of seawater turbidity and RAP234 at station SR3 in the Arctic Ocean
-
[1] 林武辉. 高纬度边缘海海洋生物泵的多同位素示踪研究[D]. 清华大学博士学位论文, 2015: 126. LIN Wuhui. Marine biological carbon pumps and their tracing using multi-isotope in the high latitude marginal seas[D]. Doctor Dissertation of Tsinghua University, 2015: 126.
[2] 林武辉, 陈立奇, 余雯, 等. 白令海和楚科奇海陆架区的生源物质埋藏通量研究[J]. 极地研究, 2016, 28(2):194-202. [LIN Wuhui, CHEN Liqi, YU Wen, et al. Burial fluxes of biogenic materials in the Bering Sea and Chukchi Sea [J]. Chinese Journal of Polar Research, 2016, 28(2): 194-202. [3] Lin W H, Chen L Q, Zeng S, et al. Residual β activity of particulate 234Th as a novel proxy for tracking sediment resuspension in the ocean [J]. Scientific Reports, 2016, 6: 27069. doi: 10.1038/srep27069
[4] 黄奕普, 陈敏. 海洋同位素示踪技术研究进展[J]. 厦门大学学报: 自然科学版, 2001, 40(2):512-523. [HUANG Yipu, CHEN Min. Progress in the isotope tracer technique for marine science [J]. Journal of Xiamen University: Natural Science, 2001, 40(2): 512-523. [5] 毕倩倩, 杜金洲. 海洋环境中放射性分析及其应用[J]. 核化学与放射化学, 2015, 37(4):193-206. [BI Qianqian, DU Jinzhou. Radio-analysis and its application in the marine environment [J]. Journal of Nuclear and Radiochemistry, 2015, 37(4): 193-206. doi: 10.7538/hhx.2015.37.04.0193 [6] Hong G H, Hamilton T F, Baskaran M, et al. Applications of anthropogenic radionuclides as tracers to investigate marine environmental processes[M]//Baskaran M. Handbook of Environmental Isotope Geochemistry. Berlin, Heidelberg: Springer, 2012: 367-394.
[7] Rutgers Van Der Loeff M M. Uranium-Thorium decay series in the oceans overview[M]//Steele J H. Encyclopedia of Ocean Sciences. San Diego: Academic Press, 2001: 3135-3145.
[8] 刘广山. 同位素海洋学[M]. 郑州: 郑州大学出版社, 2010. LIU Guangshan. Isotopic Oceanography[M]. Zhengzhou: Zhengzhou University Press, 2010.
[9] Loose B, Kelly R P, Bigdeli A, et al. How well does wind speed predict air‐sea gas transfer in the sea ice zone? A synthesis of radon deficit profiles in the upper water column of the Arctic Ocean [J]. Journal of Geophysical Research: Oceans, 2017, 122(5): 3696-3714. doi: 10.1002/2016JC012460
[10] Hayes C T, Anderson R F, Fleisher M Q, et al. Quantifying lithogenic inputs to the North Pacific Ocean using the long-lived thorium isotopes [J]. Earth and Planetary Science Letters, 2013, 383: 16-25. doi: 10.1016/j.jpgl.2013.09.025
[11] Kadko D, Landing W M, Shelley R U. A novel tracer technique to quantify the atmospheric flux of trace elements to remote ocean regions [J]. Journal of Geophysical Research: Oceans, 2015, 120(2): 848-858. doi: 10.1002/2014JC010314
[12] Baskaran M. Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: a review [J]. Journal of Environmental Radioactivity, 2011, 102(5): 500-513. doi: 10.1016/j.jenvrad.2010.10.007
[13] Du J, Du J Z, Baskaran M, et al. Temporal variations of atmospheric depositional fluxes of 7Be and 210Pb over 8?years (2006-2013) at Shanghai, China, and synthesis of global fallout data [J]. Journal of Geophysical Research: Atmospheres, 2015, 120(9): 4323-4339. doi: 10.1002/2014JD022807
[14] Regaudie-de-Gioux A, Lasternas S, Agustí S, et al. Comparing marine primary production estimates through different methods and development of conversion equations [J]. Frontiers in Marine Science, 2014, 1: 19.
[15] Yu W, He J, Li Y, et al. Particulate organic carbon export fluxes and validation of steady state model of 234Th export in the Chukchi Sea [J]. Deep Sea Research Part II: Topical Studies in Oceanography, 2012, 81-84: 63-71. doi: 10.1016/j.dsr2.2012.03.003
[16] He J H, Yu W, Lin W H, et al. Particulate organic carbon export fluxes on Chukchi Shelf, western Arctic Ocean, derived from 210Po/210Pb disequilibrium [J]. Chinese Journal of Oceanology and Limnology, 2015, 33(3): 741-747. doi: 10.1007/s00343-015-3357-x
[17] Lin W H, Ma H, Chen L Q, et al. Decay/ingrowth uncertainty correction of 210Po/210Pb in seawater [J]. Journal of Environmental Radioactivity, 2014, 137: 22-30. doi: 10.1016/j.jenvrad.2014.06.005
[18] Cai P H, Zhao D C, Wang L, et al. Role of particle stock and phytoplankton community structure in regulating particulate organic carbon export in a large marginal sea [J]. Journal of Geophysical Research: Oceans, 2015, 120(3): 2063-2095. doi: 10.1002/2014JC010432
[19] Kadko D, Johns W. Inferring upwelling rates in the equatorial Atlantic using 7Be measurements in the upper ocean [J]. Deep Sea Research Part I: Oceanographic Research Papers, 2011, 58(6): 647-657. doi: 10.1016/j.dsr.2011.03.004
[20] Geibert W, Rutgers Van Der Loeff M M, Hanfland C, et al. Actinium-227 as a deep-sea tracer: sources, distribution and applications [J]. Earth and Planetary Science Letters, 2002, 198(1-2): 147-165. doi: 10.1016/S0012-821X(02)00512-5
[21] Ma H Y, Yang W F, Zhang L H, et al. Utilizing 210Po deficit to constrain particle dynamics in mesopelagic water, western South China Sea [J]. Geochemistry, Geophysics, Geosystems, 2017, 18(4): 1594-1607. doi: 10.1002/2017GC006899
[22] Rutgers Van Der Loeff M, Meyer R, Rudels B, et al. Resuspension and particle transport in the benthic nepheloid layer in and near Fram Strait in relation to faunal abundances and 234Th depletion [J]. Deep Sea Research Part I: Oceanographic Research Papers, 2002, 49(11): 1941-1958. doi: 10.1016/S0967-0637(02)00113-9
[23] Cai P H, Shi X M, Moore W S, et al. 224Ra: 228Th disequilibrium in coastal sediments: Implications for solute transfer across the sediment–water interface [J]. Geochimica et Cosmochimica Acta, 2014, 125: 68-84. doi: 10.1016/j.gca.2013.09.029
[24] Du J Z, Zhang J, Baskaran M. Applications of short-lived radionuclides (7Be, 210Pb, 210Po, 137Cs and 234Th) to trace the sources, transport pathways and deposition of particles/sediments in rivers, estuaries and coasts[M]//Baskaran M. Handbook of Environmental Isotope Geochemistry. Berlin, Heidelberg: Springer, 2012: 305-329.
[25] Huang D K, Du J Z, Moore W S, et al. Particle dynamics of the Changjiang Estuary and adjacent coastal region determined by natural particle-reactive radionuclides (7Be, 210Pb, and 234Th) [J]. Journal of Geophysical Research: Oceans, 2013, 118(4): 1736-1748. doi: 10.1002/jgrc.20148
[26] Wang J L, Du J Z, Baskaran M, et al. Mobile mud dynamics in the East China Sea elucidated using 210Pb, 137Cs, 7Be, and 234Th as tracers [J]. Journal of Geophysical Research: Oceans, 2016, 121(1): 224-239. doi: 10.1002/2015JC011300
[27] Moore W S. The effect of submarine groundwater discharge on the ocean [J]. Annual Review of Marine Science, 2010, 2: 59-88. doi: 10.1146/annurev-marine-120308-081019
[28] Wang G Z, Wang Z Y, Zhai W D, et al. Net subterranean estuarine export fluxes of dissolved inorganic C, N, P, Si, and total alkalinity into the Jiulong River estuary, China [J]. Geochimica et Cosmochimica Acta, 2015, 149: 103-114. doi: 10.1016/j.gca.2014.11.001
[29] Rutgers Van Der Loeff M, Cai P, Stimac I, et al. Shelf-basin exchange times of Arctic surface waters estimated from 228Th/228Ra disequilibrium [J]. Journal of Geophysical Research: Oceans, 2012, 117(C3): C03024.
[30] Charette M A, Breier C F, Henderson P B, et al. Radium-based estimates of cesium isotope transport and total direct ocean discharges from the Fukushima Nuclear Power Plant accident [J]. Biogeosciences, 2013, 10(3): 2159-2167. doi: 10.5194/bg-10-2159-2013
[31] Charette M A, Morris P J, Henderson P B, et al. Radium isotope distributions during the US GEOTRACES North Atlantic cruises [J]. Marine Chemistry, 2015, 177: 184-195. doi: 10.1016/j.marchem.2015.01.001
[32] 杨守业. 一沙一世界——藏于海底的地球环境变迁史[J]. 自然杂志, 2017, 39(5):313-319. [YANG Shouye. To see a world in a grain of sand: Environment changes recorded in global seafloor [J]. Chinese Journal of Nature, 2017, 39(5): 313-319. doi: 10.3969/j.issn.0253-9608.2017.05.001 [33] Burdige D J. Geochemistry of Marine Sediments[M]. Princeton: Princeton University Press, 2006.
[34] Liu Z F, Zhao Y L, Colin C, et al. Source-to-Sink transport processes of fluvial sediments in the South China Sea [J]. Earth-Science Reviews, 2016, 153: 238-273. doi: 10.1016/j.earscirev.2015.08.005
[35] Qiao S Q, Shi X F, Wang G Q, et al. Sediment accumulation and budget in the Bohai Sea, Yellow Sea and East China Sea [J]. Marine Geology, 2017, 390: 270-281. doi: 10.1016/j.margeo.2017.06.004
[36] 林武辉, 余克服, 王英辉, 等. 罕见的地表低辐射水平区域: 珊瑚礁区[J]. 辐射防护, 2018, 38(4):287-292. [LIN Wuhui, YU Kefu, WANG Yinghui, et al. Unusual low radiation area on the surface of the earth: coral reefs [J]. Radiation Protection, 2018, 38(4): 287-292. [37] 林武辉, 余克服, 王英辉, 等. 珊瑚礁区沉积物的极低放射性水平特征与成因[J]. 科学通报, 2018, 63(21):2173-2183. [LIN Wuhui, YU Kefu, WANG Yinghui, et al. Extremely low radioactivity in marine sediment of coral reefs and its mechanism [J]. Chinese Science Bulletin, 2018, 63(21): 2173-2183. [38] Liu X M, Lin W H. Natural radioactivity in the beach sand and soil along the coastline of Guangxi Province, China [J]. Marine Pollution Bulletin, 2018, 135: 446-450. doi: 10.1016/j.marpolbul.2018.07.057
[39] 毛远意, 林静, 黄德坤, 等. 北部湾白龙半岛邻近海域沉积物中放射性核素含量水平[J]. 应用海洋学学报, 2018, 37(2):194-202. [MAO Yuanyi, LIN Jing, HUANG Dekun, et al. Radionuclides in the surface sediments along the coast of Bailong Peninsula in Beibu Gulf [J]. Journal of Applied Oceanography, 2018, 37(2): 194-202. doi: 10.3969/J.ISSN.2095-4972.2018.02.006 [40] 杜金秋, 关道明, 姚子伟, 等. 大连近海沉积物中放射性核素分布及环境指示[J]. 中国环境科学, 2017, 37(5):1889-1895. [DU Jinqiu, GUAN Daoming, YAO Ziwei, et al. Distribution and environmental significances of radionuclides in sediments of Dalian coastal area [J]. China Environmental Science, 2017, 37(5): 1889-1895. doi: 10.3969/j.issn.1000-6923.2017.05.036 [41] Sanchez-Cabeza J A, Ruiz-Fernández A C. 210Pb sediment radiochronology: An integrated formulation and classification of dating models [J]. Geochimica et Cosmochimica Acta, 2012, 82: 183-200. doi: 10.1016/j.gca.2010.12.024
[42] Aller R C, Cochran J K. 234Th/238U disequilibrium in near-shore sediment: particle reworking and diagenetic time scales [J]. Earth and Planetary Science Letters, 1976, 29(1): 37-50. doi: 10.1016/0012-821X(76)90024-8
[43] Corbett D R, Mckee B, Duncan D. An evaluation of mobile mud dynamics in the Mississippi River deltaic region [J]. Marine Geology, 2004, 209(1-4): 91-112. doi: 10.1016/j.margeo.2004.05.028
[44] Moberg F, Folke C. Ecological goods and services of coral reef ecosystems [J]. Ecological Economics, 1999, 29(2): 215-233. doi: 10.1016/S0921-8009(99)00009-9
[45] Hughes T P, Barnes M L, Bellwood D R, et al. Coral reefs in the Anthropocene [J]. Nature, 2017, 546(7656): 82-90. doi: 10.1038/nature22901
[46] McCulloch M, Fallon S, Wyndham T, et al. Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement [J]. Nature, 2003, 421(6924): 727-730. doi: 10.1038/nature01361
[47] Jones R, Bessell-Browne P, Fisher R, et al. Assessing the impacts of sediments from dredging on corals [J]. Marine Pollution Bulletin, 2016, 102(1): 9-29. doi: 10.1016/j.marpolbul.2015.10.049
[48] Wang J L, Du J Z, Bi Q Q. Natural radioactivity assessment of surface sediments in the Yangtze Estuary [J]. Marine Pollution Bulletin, 2017, 114(1): 602-608. doi: 10.1016/j.marpolbul.2016.09.040
[49] Huang D K, Du J Z, Deng B, et al. Distribution patterns of particle-reactive radionuclides in sediments off eastern Hainan Island, China: implications for source and transport pathways [J]. Continental Shelf Research, 2013, 57: 10-17. doi: 10.1016/j.csr.2012.04.019
[50] Wang Q D, Song J M, Li X G, et al. Environmental radionuclides in a coastal wetland of the Southern Laizhou Bay, China [J]. Marine Pollution Bulletin, 2015, 97(1-2): 506-511. doi: 10.1016/j.marpolbul.2015.05.035
[51] Zhou P, Li D M, Li H T, et al. Distribution of radionuclides in a marine sediment core off the waterspout of the nuclear power plants in Daya Bay, northeastern South China Sea [J]. Journal of Environmental Radioactivity, 2015, 145: 102-112. doi: 10.1016/j.jenvrad.2015.03.018
[52] Yu K N, Guan Z J, Stokes M J, et al. Natural and artificial radionuclides in seabed sediments of Hong Kong [J]. The International Journal of Radiation Applications and Instrumentation. Part E: Nuclear Geophysics, 1994, 8(1): 45-48.
[53] 赵峰, 吴梅桂, 周鹏, 等. 黄茅海—广海湾及其邻近海域表层沉积物中γ放射性核素含量水平[J]. 热带海洋学报, 2015, 34(4):77-82. [ZHAO Feng, WU Meigui, ZHOU Peng, et al. Radionuclides in surface sediments from the Huangmaohai Estuary-Guanghai Bay and its adjacent sea area of the South China Sea [J]. Journal of Tropical Oceanography, 2015, 34(4): 77-82. doi: 10.3969/j.issn.1009-5470.2015.04.011 [54] 林武辉, 陈立奇, 马豪, 等. 日本福岛核事故后的海洋放射性监测进展[J]. 中国环境科学, 2015, 35(1):269-276. [LIN Wuhui, CHEN Liqi, MA Hao, et al. Review on monitoring marine radioactivity since the Fukushima Nuclear Accident [J]. China Environmental Science, 2015, 35(1): 269-276. [55] Baskaran M. Dating of biogenic and inorganic carbonates using 210Pb-226Ra disequilibrium method: a review[M]//Baskaran M. Handbook of Environmental Isotope Geochemistry. Berlin, Heidelberg: Springer, 2012: 789-809.
[56] Saha N, Webb G E, Zhao J X. Coral skeletal geochemistry as a monitor of inshore water quality [J]. Science of the Total Environment, 2016, 566-567: 652-684. doi: 10.1016/j.scitotenv.2016.05.066
[57] Hart D E, Kench P S. Carbonate production of an emergent reef platform, Warraber Island, Torres Strait, Australia [J]. Coral Reefs, 2007, 26(1): 53-68. doi: 10.1007/s00338-006-0168-8
[58] Łącka M, Pawłowska J, Zajączkowski M. New methods in the reconstruction of Arctic marine palaeoenvironments[M]//Zielinski T, Weslawski M, Kuliński K. Impact of Climate Changes on Marine Environments. Cham: Springer, 2015: 127-148.
[59] Oguri K, Harada N, Tadai O. Excess 210Pb and 137Cs concentrations, mass accumulation rates, and sedimentary processes on the Bering Sea continental shelf [J]. Deep Sea Research Part II: Topical Studies in Oceanography, 2012, 61-64: 193-204. doi: 10.1016/j.dsr2.2011.03.007
[60] Kuzyk Z Z A, Gobeil C, Macdonald R W. 210Pb and 137Cs in margin sediments of the Arctic Ocean: controls on boundary scavenging [J]. Global Biogeochemical Cycles, 2013, 27(2): 422-439. doi: 10.1002/gbc.20041
[61] 曾文义, 程汉良, 曾宪章, 等. 厦门港的淤积现状及防淤建议[J]. 海洋通报, 1991, 10(1):45-49. [ZENG Wenyi, CHENG Hanliang, ZENG Xianzhang, et al. Situation of modern sedimentation and propositions of preventing siltation in Xiamen Harbour [J]. Marine Science Bulletin, 1991, 10(1): 45-49. [62] 刘广山. 210Pb过剩法与中国海的现代沉积物测年[M]//刘广山. 海洋放射年代学. 厦门: 厦门大学出版社, 2016: 106-136. LIU Guangshan. 210Pb excess method and modern sediment dating in the China Sea[M]//LIU Guangshan. Marine Radiological Chronology. Xiamen: Xiamen University Press, 2016: 106-136.]
[63] 潘少明, 王雪瑜, SMITH J N. 海南岛洋浦港现代沉积速率[J]. 沉积学报, 1994, 12(2):86-93. [PAN Shaoming, WANG Xueyu, SMITH J N. Recent sedimentation rates in Yangpu Harbour on Hainan Island [J]. Acta Sedimentologica Sinica, 1994, 12(2): 86-93. [64] 潘少明, 施晓东, SMITH J N. 海南岛三亚港现代沉积速率的研究[J]. 海洋与湖沼, 1995, 26(2):132-137. [PAN Shaoming, SHI Xiaodong, SMITH J N. Determination of recent sedimentation rates in Sanya Harbour, Hainan Island [J]. Oceanologia et Limnologia Sinica, 1995, 26(2): 132-137. doi: 10.3321/j.issn:0029-814X.1995.02.003 [65] 刘志勇, 潘少明, 程功弼, 等. 珠江口沉积物210Pb分布特征及环境意义[J]. 沉积学报, 2010, 28(1):166-175. [LIU Zhiyong, PAN Shaoming, CHENG Gongbi, et al. 210Pb characteristic in the sediment cores from the Pearl River Mouth and its environmental implication [J]. Acta Sedimentologica Sinica, 2010, 28(1): 166-175. [66] Li P Y, Wang Y H, Huang W Y, et al. Sixty-Year sedimentary record of DDTs, HCHs, CHLs and Endosulfan from emerging development gulfs: a case study in the Beibu Gulf, South China Sea [J]. Bulletin of Environmental Contamination and Toxicology, 2014, 92(1): 23-29. doi: 10.1007/s00128-013-1130-4
[67] McCave I N. Local and global aspects of the bottom nepheloid layers in the world ocean [J]. Netherlands Journal of Sea Research, 1986, 20(2-3): 167-181. doi: 10.1016/0077-7579(86)90040-2
[68] Boudreau B P. A one-dimensional model for bed-boundary layer particle exchange [J]. Journal of Marine Systems, 1997, 11(3-4): 279-303. doi: 10.1016/S0924-7963(96)00127-3
[69] Middag R, Van Hulten M M P, Van Aken H M, et al. Dissolved aluminium in the ocean conveyor of the West Atlantic Ocean: effects of the biological cycle, scavenging, sediment resuspension and hydrography [J]. Marine Chemistry, 2015, 177: 69-86. doi: 10.1016/j.marchem.2015.02.015
[70] Hall I R, Schmidt S, McCave I N, et al. Particulate matter distribution and 234Th/238U disequilibrium along the Northern Iberian Margin: implications for particulate organic carbon export [J]. Deep Sea Research Part I: Oceanographic Research Papers, 2000, 47(4): 557-582. doi: 10.1016/S0967-0637(99)00065-5
[71] Rutgers Van Der Loeff M M, Boudreau B P. The effect of resuspension on chemical exchanges at the sediment-water interface in the deep sea — A modelling and natural radiotracer approach [J]. Journal of Marine Systems, 1997, 11(3-4): 305-342. doi: 10.1016/S0924-7963(96)00128-5
[72] Turley C. Bacteria in the cold deep-sea benthic boundary layer and sediment-water interface of the NE Atlantic [J]. FEMS Microbiology Ecology, 2000, 33(2): 89-99.
[73] 汪卫国, 方建勇, 陈莉莉, 等. 楚科奇海悬浮体含量分布及其颗粒组分特征[J]. 极地研究, 2014, 26(1):79-88. [WANG Weiguo, FANG Jianyong, CHEN Lili, et al. The distribution and composition of suspended particles in the Chukchi Sea [J]. Chinese Journal of Polar Research, 2014, 26(1): 79-88. [74] Woodgate R A, Aagaard K, Weingartner T J. A year in the physical oceanography of the Chukchi Sea: Moored measurements from autumn 1990-1991 [J]. Deep Sea Research Part II: Topical Studies in Oceanography, 2005, 52(24-26): 3116-3149. doi: 10.1016/j.dsr2.2005.10.016
[75] White W M. Geochemistry[M]. Chichester, West Sussex Hoboken: John Wiley & Sons, 2013.
-
期刊类型引用(5)
1. 李彦杰，朱友生，陈冠军，王姝，王微微. 基于AUV观测数据的南海东沙北部浅表层精细地质特征及其灾害因素分析. 热带海洋学报. 2023(01): 114-123 . 
百度学术
2. 杨天宇，邹立，赵彦彦，宋晓帅，权永峥，贾永刚. 南海东北部上层沉积物有机碳的沉积特征. 海洋环境科学. 2022(01): 16-23 . 百度学术
3. 王大伟，曾凡长，王微微，孙悦. 海底冲沟——深水沉积输运系统的“毛细血管”. 地球科学进展. 2022(04): 331-343 . 百度学术
4. Xishuang Li，Chengyi Zhang，Baohua Liu，Lejun Liu. Mounded seismic units in the modern canyon system in the Shenhu area, northern South China Sea: Sediment deformation, depositional structures or the mixed system?. Acta Oceanologica Sinica. 2022(09): 107-116 . 必应学术
5. 龚广传，李磊，何旺，张威，高毅凡，程琳燕，杨志鹏. 块体搬运沉积顶面沉积过程模拟--以南海北部坡为例. 海洋地质前沿. 2022(12): 75-83 . 百度学术
其他类型引用(0)
下载:
计量
- 文章访问数: 3386
- HTML全文浏览量: 773
- PDF下载量: 85
- 被引次数: 5
