Geomorphology最新文献

Seasonal vertical accretion in different hydro-geomorphic environments of Indian Sundarban: Assessing the role of mangroves in mitigating sea level rise impacts 印度巽他班不同水文地貌环境中的季节性垂直增生：评估红树林在减轻海平面上升影响方面的作用

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-31 DOI: 10.1016/j.geomorph.2024.109493

The Indian Sundarban, renowned for its unique hydro-geomorphic diversity, faces rising threats from sea level rise, necessitating an examination of the spatio-temporal variation of vertical accretion and the role played by mangroves in mitigating these impacts. As such, fifteen transects were chosen across buffer and transition zones of Indian Sundarban, each equipped with 4–6 sedimentation pins, to gauge accretion rates in premonsoon, monsoon, and postmonsoon season during period March 2020 to March 2022, considering diverse hydro-geomorphic attributes. The vertical accretion rate exhibits a curvilinear pattern, ascending from the lower seafront zone towards the middle of the estuarine region, reaching a peak, and subsequently declining towards the upper estuarine zones. Specifically, in the seafront zone, the yearly mean accretion (focusing solely on accretion and excluding subsidence) ranges between 5 and 10 mm/year, while in the middle estuarine region, it increases to an average of 38.1 ± 9.44 mm/year. However, in the upper zone, the yearly mean accretion decreases slightly to approximately 17.71 ± 9.54 mm/year. Similar patterns are observed when considering the distance from the riverfront to the interior of the mangrove zones. Seasonal analysis demonstrates that the postmonsoon period exhibits the highest accretion, followed by the premonsoon season, while the monsoon tends to be erosional in nature. Mangrove zonation, and subsequent distribution of root height, root diameter, root density, tree density, tree basal area, inundation frequency, current speed, variation in suspended sediment concentration were identified as influential factors affecting vertical accretion rates. Based on multiple regression analysis, root density, inundation frequency, and tree density demonstrated moderate-positive correlations with vertical accretion, whereas distance from the riverfront, root height, and root diameter displayed negative correlations. This study enhances our understanding of the intricate processes behind vertical accretion in the Sundarban, offering valuable insights for future research and advancing discussions on the broader implications of climate change in coastal regions.

印度巽他湾以其独特的水文地质多样性而闻名于世，它面临着海平面上升带来的日益严重的威胁，因此有必要对垂直增生的时空变化以及红树林在减轻这些影响方面所起的作用进行研究。因此，我们在印度巽他班的缓冲区和过渡区选择了 15 个横断面，每个横断面配备 4-6 个沉积针，以测量 2020 年 3 月至 2022 年 3 月期间季风前、季风和季风后季节的增生率，同时考虑到不同的水文地质属性。垂直吸积率呈现曲线模式，从下部海滨区向河口区中部上升，达到峰值，随后向河口区上部下降。具体而言，在海滨区，年平均增量（仅指增量，不包括沉降）介于 5 至 10 毫米/年之间，而在河口区中部，年平均增量增至 38.1 ± 9.44 毫米/年。然而，在上层区域，年平均增量略有下降，约为 17.71 ± 9.54 毫米/年。从河岸到红树林区内部的距离也可以观察到类似的模式。季节分析表明，季风后时期的增殖量最大，其次是季风前时期，而季风时期往往具有侵蚀性。红树林分区以及随后的根高分布、根直径、根密度、树木密度、树木基部面积、淹没频率、水流速度、悬浮沉积物浓度变化被确定为影响垂直增殖率的影响因素。根据多元回归分析，根系密度、淹没频率和树木密度与垂直增殖呈中度正相关，而与河岸的距离、根系高度和根系直径呈负相关。这项研究加深了我们对巽他班垂直增生背后复杂过程的理解，为未来研究提供了宝贵的见解，并推动了有关气候变化对沿海地区更广泛影响的讨论。

{"title":"Seasonal vertical accretion in different hydro-geomorphic environments of Indian Sundarban: Assessing the role of mangroves in mitigating sea level rise impacts","authors":"","doi":"10.1016/j.geomorph.2024.109493","DOIUrl":"10.1016/j.geomorph.2024.109493","url":null,"abstract":"<div><div>The Indian Sundarban, renowned for its unique hydro-geomorphic diversity, faces rising threats from sea level rise, necessitating an examination of the spatio-temporal variation of vertical accretion and the role played by mangroves in mitigating these impacts. As such, fifteen transects were chosen across buffer and transition zones of Indian Sundarban, each equipped with 4–6 sedimentation pins, to gauge accretion rates in premonsoon, monsoon, and postmonsoon season during period March 2020 to March 2022, considering diverse hydro-geomorphic attributes. The vertical accretion rate exhibits a curvilinear pattern, ascending from the lower seafront zone towards the middle of the estuarine region, reaching a peak, and subsequently declining towards the upper estuarine zones. Specifically, in the seafront zone, the yearly mean accretion (focusing solely on accretion and excluding subsidence) ranges between 5 and 10 mm/year, while in the middle estuarine region, it increases to an average of 38.1 ± 9.44 mm/year. However, in the upper zone, the yearly mean accretion decreases slightly to approximately 17.71 ± 9.54 mm/year. Similar patterns are observed when considering the distance from the riverfront to the interior of the mangrove zones. Seasonal analysis demonstrates that the postmonsoon period exhibits the highest accretion, followed by the premonsoon season, while the monsoon tends to be erosional in nature. Mangrove zonation, and subsequent distribution of root height, root diameter, root density, tree density, tree basal area, inundation frequency, current speed, variation in suspended sediment concentration were identified as influential factors affecting vertical accretion rates. Based on multiple regression analysis, root density, inundation frequency, and tree density demonstrated moderate-positive correlations with vertical accretion, whereas distance from the riverfront, root height, and root diameter displayed negative correlations. This study enhances our understanding of the intricate processes behind vertical accretion in the Sundarban, offering valuable insights for future research and advancing discussions on the broader implications of climate change in coastal regions.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Automatic extraction of Transverse Aeolian Ridges (TARs) and analysis of landform influence for the Zhurong landing area on Mars 火星祝融着陆区横向风化脊（TAR）的自动提取及地貌影响分析

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-31 DOI: 10.1016/j.geomorph.2024.109489

The morphology and surface characteristics of Transverse Aeolian Ridges (TARs) reflect the recent and current environmental evolution of Mars. This study investigates the influence of typical Martian non-aeolian landforms impacted on the distribution and morphology of TARs using multi-source high-resolution orbiter images in the Zhurong rover's landing region at the south of Utopian Plain. This study proposes an automatic and effective approach for extracting TARs, while classifying their types and estimating their geometric parameters, including length, width, height, and angle. The obtained results confirm the effectiveness of the proposed method. In the Zhurong rover's landing region, TARs in flat areas have a sparse distribution and simple morphology. However, TARs are more concentrated and diverse in morphology around typical non-aeolian landforms such as cones and troughs. The orientation of TARs is determined by wind direction, and their width is affected by sediment richness. The morphology and distribution of TARs are also influenced by typical non-aeolian landforms, which modify local wind fields and sediments.

横向风化脊（TARs）的形态和表面特征反映了火星近期和当前的环境演变。本研究利用祝融号探测器在乌托邦平原南部着陆区的多源高分辨率轨道器图像，研究了典型火星非风化地貌对TARs分布和形态的影响。本研究提出了一种自动、有效的方法来提取TAR，同时对其类型进行分类，并估算其几何参数，包括长度、宽度、高度和角度。研究结果证实了所提方法的有效性。在祝融号探测器着陆区，平坦区域的TAR分布稀疏，形态简单。然而，在典型的非风化地貌（如圆锥和槽谷）周围，TARs 的分布更为集中，形态也更为多样。TARs的走向由风向决定，其宽度受沉积物丰富程度的影响。TARs的形态和分布还受到典型的非风成陆地貌的影响，这些地貌改变了当地的风场和沉积物。

引用次数: 0

Unveiling gully erosion susceptibility: A semi-quantitative modeling approach integrated with field data in contrasting landscapes and climate regions 揭示沟谷侵蚀的易发性：半定量建模方法与对比地貌和气候区域的实地数据相结合

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-31 DOI: 10.1016/j.geomorph.2024.109485

This study addresses the challenge of mapping gully erosion susceptibility, which is often hindered by limited observed data, the complexity of controlling factors, and the uncertainties associated with characterizing these factors. We utilized a semi-quantitative modeling approach that integrates field-based data and ten controlling factors in the Chemoga watershed of Ethiopia's Upper Blue Nile basin. The resulting gully erosion susceptibility map was compared with a random forest-based approach to assess the methodological applicability. Additionally, an independent dataset from adjacent watersheds was used to validate the approach. The findings revealed that certain landscape positions with specific elevation ranges and slope steepness were more susceptible to gully erosion due to factors such as rainfall, lithological formations, soil characteristics, and agricultural activities. Approximately 10 % of the watershed area was affected by gully erosion, with varying susceptibility levels. The comparison between the semi-quantitative and random forest approaches demonstrates a total agreement of around 58 %, with minimal differences in susceptibility classes. The study also highlights a strong agreement between simulated and observed susceptibility maps, with a 76 % PBIAS (Percent Bias) value for the simulation and a lower 48 % agreement for the random forest approach. Furthermore, in the adjacent watershed, 65 % of the area exhibits no discrepancies between observed and simulated maps. This suggests that the semi-quantitative approach is effective in extrapolating gully erosion susceptibility when detailed data is limited, offering a cost-effective and efficient solution. The study emphasizes the utility of the semi-quantitative modeling approach in mapping gully erosion susceptibility and its potential for practical applications in land management and intervention strategies.

这项研究解决了绘制沟谷侵蚀易发性地图所面临的挑战，因为观测数据有限、控制因素复杂以及描述这些因素所带来的不确定性往往会阻碍绘制工作。我们采用了一种半定量建模方法，将埃塞俄比亚青尼罗河上游流域 Chemoga 流域的实地数据和十个控制因素整合在一起。我们将绘制的沟壑侵蚀易感性地图与基于随机森林的方法进行了比较，以评估该方法的适用性。此外，还使用了邻近流域的独立数据集来验证该方法。研究结果表明，受降雨、岩层、土壤特性和农业活动等因素的影响，某些具有特定海拔范围和坡度的地貌位置更容易受到沟壑侵蚀。约有 10% 的流域面积受到沟壑侵蚀的影响，易受影响的程度各不相同。半定量方法与随机森林方法之间的比较显示，两者之间的总体一致性约为 58%，易受侵蚀程度等级之间的差异极小。研究还强调了模拟和观测易感性地图之间的高度一致性，模拟的 PBIAS（偏差百分比）值为 76%，而随机森林方法的一致性较低，仅为 48%。此外，在邻近流域，65% 的区域观测到的地图与模拟地图没有差异。这表明，在详细数据有限的情况下，半定量方法可有效推断沟谷侵蚀易发性，是一种经济高效的解决方案。这项研究强调了半定量建模方法在绘制沟壑侵蚀易发性地图方面的实用性，以及在土地管理和干预策略方面的实际应用潜力。

{"title":"Unveiling gully erosion susceptibility: A semi-quantitative modeling approach integrated with field data in contrasting landscapes and climate regions","authors":"","doi":"10.1016/j.geomorph.2024.109485","DOIUrl":"10.1016/j.geomorph.2024.109485","url":null,"abstract":"<div><div>This study addresses the challenge of mapping gully erosion susceptibility, which is often hindered by limited observed data, the complexity of controlling factors, and the uncertainties associated with characterizing these factors. We utilized a semi-quantitative modeling approach that integrates field-based data and ten controlling factors in the Chemoga watershed of Ethiopia's Upper Blue Nile basin. The resulting gully erosion susceptibility map was compared with a random forest-based approach to assess the methodological applicability. Additionally, an independent dataset from adjacent watersheds was used to validate the approach. The findings revealed that certain landscape positions with specific elevation ranges and slope steepness were more susceptible to gully erosion due to factors such as rainfall, lithological formations, soil characteristics, and agricultural activities. Approximately 10 % of the watershed area was affected by gully erosion, with varying susceptibility levels. The comparison between the semi-quantitative and random forest approaches demonstrates a total agreement of around 58 %, with minimal differences in susceptibility classes. The study also highlights a strong agreement between simulated and observed susceptibility maps, with a 76 % PBIAS (Percent Bias) value for the simulation and a lower 48 % agreement for the random forest approach. Furthermore, in the adjacent watershed, 65 % of the area exhibits no discrepancies between observed and simulated maps. This suggests that the semi-quantitative approach is effective in extrapolating gully erosion susceptibility when detailed data is limited, offering a cost-effective and efficient solution. The study emphasizes the utility of the semi-quantitative modeling approach in mapping gully erosion susceptibility and its potential for practical applications in land management and intervention strategies.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Meteorological factors control debris slides and debris flows in a high-Arctic glacier basin (Ny-Ålesund, Svalbard) 控制北极高纬度冰川盆地（斯瓦尔巴特群岛尼-奥勒松）碎屑滑坡和碎屑流的气象因素

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-31 DOI: 10.1016/j.geomorph.2024.109492

Landslide processes are one of the dominant agents of erosion and sediment transport on sediment-mantled slopes in arctic environments. Increased landslide activity is anticipated as climate change is projected to decrease mountain slope stability. High-Arctic environments, such as Svalbard, serve as crucial observatories for investigating current and future slope dynamics within a changing climate, particularly due to arctic amplification effects. Despite the significance of Arctic regions, empirical evidence in high latitudes is often lacking. This scarcity can be attributed to the absence of long-term, high-resolution terrain data with sufficient temporal resolution to assess the impact of meteorological boundary conditions on landscapes altered by climate change. However, addressing this gap in empirical evidence is essential for understanding the complex interplay between meteorological variables and debris slide and debris flow evolution in Arctic environments. This study presents a unique high-resolution remote sensing dataset within a high-Arctic glacier basin acquired over a 10-year period. Through the combination of terrestrial laser-scanning and an autonomous camera network, we were able to investigate the impact of meteorological boundary conditions on the trigger mechanisms of translational debris slides and debris flows and unravel paraglacial slope evolution following recent glacier retreat on the example of the Austre Lovénbreen glacier basin (Svalbard, Norway). Translational debris slides accounted for approximately 96 % (N = 147) of the total sediment flux observed, with debris flows (N = 21) acting as a secondary agent of sediment transport. The debris slide activity significantly increased between 2011 and 2021. Heavy rainfall events primarily influence the frequency and magnitude of debris slides during the hydrological summer, while the duration and intensity of the thawing period serve as the principal control for their initiation. Furthermore, a 2-year recurrence period for major debris flows (≥ 400 m³) was found, which is about 2.5 to 5 times shorter than previous estimates for the last few decades on Svalbard. In conclusion, this study highlights the impact of meteorological factors on debris slide frequency and magnitude within high-Arctic glacier basins, shedding light on the dynamics of paraglacial slope modification in Arctic environments affected by climate change.

滑坡过程是北极环境中沉积物覆盖斜坡上侵蚀和沉积物迁移的主要因素之一。由于气候变化预计会降低山坡的稳定性，因此预计滑坡活动将会增加。斯瓦尔巴群岛等北极高纬度环境是研究气候变化下当前和未来山坡动态的重要观测站，特别是由于北极放大效应。尽管北极地区非常重要，但高纬度地区往往缺乏经验证据。这种缺乏可归因于缺乏具有足够时间分辨率的长期、高分辨率地形数据，以评估气象边界条件对因气候变化而改变的地貌的影响。然而，要了解北极环境中气象变量与泥石流演变之间复杂的相互作用，解决这一经验证据方面的差距至关重要。本研究展示了一个独特的高分辨率遥感数据集，该数据集是在一个高纬度北极冰川盆地内历时 10 年采集的。通过地面激光扫描和自主相机网络的结合，我们得以研究气象边界条件对平移碎屑滑坡和碎屑流触发机制的影响，并以奥斯特勒洛韦布林冰川盆地（挪威斯瓦尔巴群岛）为例，揭示了近期冰川退缩后的副冰川斜坡演变。在观测到的沉积物总通量中，平移式泥石流约占 96%（N = 147），泥石流（N = 21）是沉积物迁移的次要媒介。2011 年至 2021 年期间，泥石流活动明显增加。暴雨事件主要影响夏季水文过程中泥石流的发生频率和规模，而解冻期的持续时间和强度则是泥石流发生的主要控制因素。此外，研究还发现，主要泥石流（≥ 400 立方米）的重现期为 2 年，比过去几十年斯瓦尔巴群岛泥石流重现期的估计值短 2.5 到 5 倍。总之，这项研究强调了气象因素对北极高纬度冰川盆地内泥石流发生频率和规模的影响，揭示了受气候变化影响的北极环境中副冰川斜坡改变的动态。

{"title":"Meteorological factors control debris slides and debris flows in a high-Arctic glacier basin (Ny-Ålesund, Svalbard)","authors":"","doi":"10.1016/j.geomorph.2024.109492","DOIUrl":"10.1016/j.geomorph.2024.109492","url":null,"abstract":"<div><div>Landslide processes are one of the dominant agents of erosion and sediment transport on sediment-mantled slopes in arctic environments. Increased landslide activity is anticipated as climate change is projected to decrease mountain slope stability. High-Arctic environments, such as Svalbard, serve as crucial observatories for investigating current and future slope dynamics within a changing climate, particularly due to arctic amplification effects. Despite the significance of Arctic regions, empirical evidence in high latitudes is often lacking. This scarcity can be attributed to the absence of long-term, high-resolution terrain data with sufficient temporal resolution to assess the impact of meteorological boundary conditions on landscapes altered by climate change. However, addressing this gap in empirical evidence is essential for understanding the complex interplay between meteorological variables and debris slide and debris flow evolution in Arctic environments. This study presents a unique high-resolution remote sensing dataset within a high-Arctic glacier basin acquired over a 10-year period. Through the combination of terrestrial laser-scanning and an autonomous camera network, we were able to investigate the impact of meteorological boundary conditions on the trigger mechanisms of translational debris slides and debris flows and unravel paraglacial slope evolution following recent glacier retreat on the example of the Austre Lovénbreen glacier basin (Svalbard, Norway). Translational debris slides accounted for approximately 96 % (<em>N</em> = 147) of the total sediment flux observed, with debris flows (<em>N</em> = 21) acting as a secondary agent of sediment transport. The debris slide activity significantly increased between 2011 and 2021. Heavy rainfall events primarily influence the frequency and magnitude of debris slides during the hydrological summer, while the duration and intensity of the thawing period serve as the principal control for their initiation. Furthermore, a 2-year recurrence period for major debris flows (≥ 400 m<sup>3</sup>) was found, which is about 2.5 to 5 times shorter than previous estimates for the last few decades on Svalbard. In conclusion, this study highlights the impact of meteorological factors on debris slide frequency and magnitude within high-Arctic glacier basins, shedding light on the dynamics of paraglacial slope modification in Arctic environments affected by climate change.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Controls on coastal bluff erosion of a drowned drumlin field: Boston Harbor, Massachusetts 被淹没的鼓浪原对海岸崖壁侵蚀的控制：马萨诸塞州波士顿港

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-31 DOI: 10.1016/j.geomorph.2024.109490

Eroding coastal bluffs pose significant risks to coastal communities, and an improved understanding of their erosional processes and mechanisms is essential for developing effective management strategies. The Boston Harbor Islands comprise more than two dozen drowned drumlins that were formed during the late-Pleistocene, many of which are now connected by spits. Exposed bluffs on the islands experience erosion due to waves and precipitation and are increasingly threatened by accelerating sea-level rise (SLR). Retreat rates for 31 bluffs along the drumlin shore, derived from orthoimagery (1995–2021) using the Digital Shoreline Analysis System add-in for ArcMap 10.8, range from 0.0 m/yr to 1.5 m/yr. These rates were examined in relation to several factors, including shoreline orientation, significant wave height during extratropical storms, till matrix composition, base elevation, bluff height, and presence of engineering structures. Clusters of bluffs with similar characteristics were identified, suggesting that high retreat rates coincide with bluffs that experience high wave energy, face the northeast and have high sand-to-mud ratios. The complexity of the Boston Harbor drumlin field and the variability of individual factors controlling erosion highlights the impracticality of developing a universal statistical model for predicting erosion rates. Rather a more suitable approach involves assessing trends among clusters of bluffs with similar characteristics. A similar approach can be taken for exploring the variability in retreat rates along other coastlines with complex or irregular bluff systems and wave fields.

侵蚀的海岸峭壁给沿海社区带来了巨大的风险，要制定有效的管理策略，就必须加深对其侵蚀过程和机理的了解。波士顿港群岛由二十多个形成于晚更新世的溺水鼓浪岛组成，其中许多鼓浪岛现在由海湾连接。岛上裸露的悬崖受到海浪和降水的侵蚀，并日益受到海平面加速上升（SLR）的威胁。使用 ArcMap 10.8 的数字海岸线分析系统插件，根据正射影像（1995-2021 年）得出的鼓浪屿沿岸 31 块悬崖的退缩率为 0.0 米/年至 1.5 米/年。这些速率与多种因素有关，包括海岸线方向、外热带风暴期间的显著波高、耕层基质成分、基底标高、悬崖高度和工程结构的存在。研究发现，具有类似特征的崖群表明，高退缩率的崖群与波浪能量高、面向东北方向以及沙泥比高的崖群相吻合。波士顿港鼓状岩区域的复杂性和控制侵蚀的各个因素的多变性突出表明，开发一个预测侵蚀率的通用统计模型是不切实际的。更合适的方法是评估具有相似特征的悬崖群的趋势。可以采用类似的方法来探索其他海岸线上具有复杂或不规则悬崖系统和波浪场的退缩率的变化情况。

{"title":"Controls on coastal bluff erosion of a drowned drumlin field: Boston Harbor, Massachusetts","authors":"","doi":"10.1016/j.geomorph.2024.109490","DOIUrl":"10.1016/j.geomorph.2024.109490","url":null,"abstract":"<div><div>Eroding coastal bluffs pose significant risks to coastal communities, and an improved understanding of their erosional processes and mechanisms is essential for developing effective management strategies. The Boston Harbor Islands comprise more than two dozen drowned drumlins that were formed during the late-Pleistocene, many of which are now connected by spits. Exposed bluffs on the islands experience erosion due to waves and precipitation and are increasingly threatened by accelerating sea-level rise (SLR). Retreat rates for 31 bluffs along the drumlin shore, derived from orthoimagery (1995–2021) using the Digital Shoreline Analysis System add-in for ArcMap 10.8, range from 0.0 m/yr to 1.5 m/yr. These rates were examined in relation to several factors, including shoreline orientation, significant wave height during extratropical storms, till matrix composition, base elevation, bluff height, and presence of engineering structures. Clusters of bluffs with similar characteristics were identified, suggesting that high retreat rates coincide with bluffs that experience high wave energy, face the northeast and have high sand-to-mud ratios. The complexity of the Boston Harbor drumlin field and the variability of individual factors controlling erosion highlights the impracticality of developing a universal statistical model for predicting erosion rates. Rather a more suitable approach involves assessing trends among clusters of bluffs with similar characteristics. A similar approach can be taken for exploring the variability in retreat rates along other coastlines with complex or irregular bluff systems and wave fields.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Scale-dependent interactions in coastal biogeomorphic landscapes: Pioneer both inhibits and facilitates primary foredune builder across spatial scales 沿海生物地貌景观中规模依赖性的相互作用：先锋在不同空间尺度上既抑制又促进原生前沙丘的形成

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-30 DOI: 10.1016/j.geomorph.2024.109486

Ecosystem engineers often drive landscape formation and vegetation succession by modifying environmental conditions. Along the Northwestern European coast, dune formation is classically believed to be pioneered by sand couch (Elytrigia juncea), followed by the primary foredune builder marram grass (Calamagrostis arenaria, formerly Ammophila arenaria) once sufficiently large dunes have formed. However, these ideas lack experimental validation, leaving the specific relationship between sand couch, the landscape they form, and marram grass establishment unknown. Here, we experimentally investigated this relationship by planting 975 young marram grass plants in two sand couch dominated, embryonic dune systems. Using structural equation models, we examined the effect of sand couch and the landscape attributes (i.e., elevation, distance to sea and elevation change) on marram grass establishment. Results reveal indirect local inhibition by sand couch via landscape modifications on survival of establishing marram grass. Specifically, sand couch elevated the environment. In turn, elevated areas eroded (i.e., changed in elevation) more in winter, which was the key factor reducing marram grass survival. At the landscape scale, however, we observed the highest survival in relatively stable and sheltered microsites formed because of sand couch induced dune building. While the indirect local inhibition by sand couch for marram grass survival was found at both locations, the direct effect of sand couch on marram grass survival and shoot formation were location and thus context dependent. For marram grass survival, the relation with sand couch was neutral in exposed and positive in sheltered conditions and for shoot formation it was negative in exposed and neutral in sheltered conditions. Similar to scale-dependent interactions found in other biogeomorphic landscapes (e.g., salt marshes, seagrass, mussel beds), we suggest that interspecific facilitation acts on larger spatial scales rather than the commonly suggested small-scale facilitation through created elevation. More specifically, we suggest that dune formation by pioneer species leads to the creation of stable and sheltered microsites beneficial for establishment of later successional species at the landscape-scale.

生态系统工程师通常通过改变环境条件来推动地貌形成和植被演替。在欧洲西北部沿海地区，人们通常认为沙丘是由沙榻（Elytrigia juncea）率先形成的，一旦形成足够大的沙丘，沙丘前的主要植被马兰草（Calamagrostis arenaria，原名 Ammophila arenaria）就会随之形成。然而，这些观点缺乏实验验证，因此沙榻、沙榻形成的地貌和金缕梅草形成之间的具体关系尚不清楚。在这里，我们在两个以沙榻为主的胚胎沙丘系统中种植了 975 株幼小的马兰草，对这种关系进行了实验研究。利用结构方程模型，我们研究了沙垫和景观属性（即海拔、距海距离和海拔变化）对马兰草生长的影响。结果表明，沙榻通过地貌改变间接抑制了金盏菊的成活。具体来说，沙榻抬高了环境。反过来，高地在冬季受到的侵蚀（即海拔高度变化）更大，这是降低马蔺存活率的关键因素。然而，在地貌尺度上，我们观察到，由于沙榻引起的沙丘形成，在相对稳定和遮蔽的微观环境中，马蔺的存活率最高。虽然在这两个地点都发现了沙垫对金盏菊存活率的间接局部抑制作用，但沙垫对金盏菊存活率和新芽形成的直接影响是因地制宜的。就马蔺的存活率而言，沙垫与马蔺存活率的关系在暴露条件下为中性，在遮蔽条件下为阳性；就新芽形成而言，沙垫与新芽形成的关系在暴露条件下为负性，在遮蔽条件下为中性。与在其他生物地貌景观（如盐沼、海草、贻贝床）中发现的规模依赖性相互作用类似，我们认为种间促进作用是在更大的空间尺度上发生的，而不是通常所说的通过所创造的海拔高度进行小规模的促进作用。更具体地说，我们认为先驱物种形成的沙丘会创造出稳定和遮蔽的微生境，有利于后继物种在景观尺度上的建立。

{"title":"Scale-dependent interactions in coastal biogeomorphic landscapes: Pioneer both inhibits and facilitates primary foredune builder across spatial scales","authors":"","doi":"10.1016/j.geomorph.2024.109486","DOIUrl":"10.1016/j.geomorph.2024.109486","url":null,"abstract":"<div><div>Ecosystem engineers often drive landscape formation and vegetation succession by modifying environmental conditions. Along the Northwestern European coast, dune formation is classically believed to be pioneered by sand couch (<em>Elytrigia juncea</em>), followed by the primary foredune builder marram grass (<em>Calamagrostis arenaria</em>, formerly <em>Ammophila arenaria</em>) once sufficiently large dunes have formed. However, these ideas lack experimental validation, leaving the specific relationship between sand couch, the landscape they form, and marram grass establishment unknown. Here, we experimentally investigated this relationship by planting 975 young marram grass plants in two sand couch dominated, embryonic dune systems. Using structural equation models, we examined the effect of sand couch and the landscape attributes (i.e., elevation, distance to sea and elevation change) on marram grass establishment. Results reveal indirect local inhibition by sand couch via landscape modifications on survival of establishing marram grass. Specifically, sand couch elevated the environment. In turn, elevated areas eroded (i.e., changed in elevation) more in winter, which was the key factor reducing marram grass survival. At the landscape scale, however, we observed the highest survival in relatively stable and sheltered microsites formed because of sand couch induced dune building. While the indirect local inhibition by sand couch for marram grass survival was found at both locations, the direct effect of sand couch on marram grass survival and shoot formation were location and thus context dependent. For marram grass survival, the relation with sand couch was neutral in exposed and positive in sheltered conditions and for shoot formation it was negative in exposed and neutral in sheltered conditions. Similar to scale-dependent interactions found in other biogeomorphic landscapes (e.g., salt marshes, seagrass, mussel beds), we suggest that interspecific facilitation acts on larger spatial scales rather than the commonly suggested small-scale facilitation through created elevation. More specifically, we suggest that dune formation by pioneer species leads to the creation of stable and sheltered microsites beneficial for establishment of later successional species at the landscape-scale.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphometric characteristics of glacial cirques and former glaciers in the Geyik Mountains, Western Taurus, Türkiye 图尔基耶西金牛座盖伊克山冰川圈和前冰川的形态特征

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-30 DOI: 10.1016/j.geomorph.2024.109474

Using the Glacier reconstruction (GlaRe) toolbox, reconstructions of former glaciers in the Geyik Mountains, part of the Taurus Mountain system in southern Türkiye, show that an area of 132.5 km² was glaciated in the last major glaciation, which left clear terminal and hummocky moraines. Glaciers were 1.4 to 12 km long and those from 49 cirques merged to form a broad 75 km² piedmont glacier in the Namaras Valley, up to 400 m thick. A thorough analysis of morphometry of the 98 Geyik cirques, using the revised Automated Cirque Metric Extraction version 2 (ACME2) toolbox, shows that they are relatively small, with limited widths: the median length/width ratio of 1.29 is unusually high. With size, length and width increase faster than depth, demonstrating strong static allometry. Maximum slope averages 59°, minimum 3.3° and axial 25°. A combination of low hypsometric integral, high axial profile closure and high axial height-length integral is proposed as a measure of cirque development.

The main summits are on sharp ridges on cirque crests, showing that they have been lowered by glacial erosion (by cirque development). Glaciation was strongly asymmetric, with cirque vector mean aspect between northeast and north-northeast. This shows the dominance of solar radiation effects, with some modification from westerly winds. Glacier palaeo- Equilibrium Line Altitudes (pELAs) rise northeastwards and cirque floor minimum altitudes (CFAs) rise toward east-northeast, both showing the importance of moist air from the Mediterranean, 38–55 km to the southwest. pELA averages 2208 m above sea level (a.s.l.) (2277 m area-weighted); CFA averages 2234 m. CFA varies mainly with summit altitudes; where related palaeoglaciers are short CFA is somewhat below pELA, but for longer ones it is above. The most likely palaeoclimate to form these glaciers involves a precipitation increase of 53–72 % with a temperature fall of 8 °C compared with present-day. The cirques formed under similar or less severe conditions.

利用冰川重建（GlaRe）工具箱，对土耳其南部金牛山系盖伊克山脉（Geyik Mountains）的前冰川进行了重建，结果表明，在上一次大冰川作用中，132.5 平方公里的区域被冰川覆盖，并留下了清晰的末端冰碛和沼泽冰碛。冰川长 1.4 至 12 千米，49 个冰川圈的冰川汇合在一起，在纳马拉斯山谷形成了 75 平方千米宽的山麓冰川，厚度达 400 米。使用修订后的自动冰川度量提取工具箱 2（ACME2）对 98 个盖伊克冰川圈的形态进行的全面分析表明，这些冰川圈相对较小，宽度有限：中位数长宽比为 1.29，异常之高。随着体积的增大，长度和宽度的增加速度快于深度，显示出很强的静态几何特性。最大斜度平均为 59°，最小为 3.3°，轴向为 25°。主要山顶位于盘旋山脊上的尖锐山脊上，表明这些山顶因冰川侵蚀（盘旋发育）而降低。冰川作用具有很强的不对称性，山圈矢量的平均方向介于东北和东北偏北之间。这表明太阳辐射效应占主导地位，西风对其有一定的影响。冰川古平衡线海拔（pELA）向东北方向升高，峡谷底最低海拔（CFA）向东北偏东方向升高，两者都显示了来自西南 38-55 公里处地中海的潮湿空气的重要性。CFA主要随山顶高度而变化；相关古冰川较短时，CFA略低于pELA，但较长时则高于pELA。形成这些冰川的最可能的古气候是降水量比现在增加 53-72%，温度比现在下降 8 °C。冰川圈是在类似或不太严重的条件下形成的。

{"title":"Morphometric characteristics of glacial cirques and former glaciers in the Geyik Mountains, Western Taurus, Türkiye","authors":"","doi":"10.1016/j.geomorph.2024.109474","DOIUrl":"10.1016/j.geomorph.2024.109474","url":null,"abstract":"<div><div>Using the Glacier reconstruction (GlaRe) toolbox, reconstructions of former glaciers in the Geyik Mountains, part of the Taurus Mountain system in southern Türkiye, show that an area of 132.5 km<sup>2</sup> was glaciated in the last major glaciation, which left clear terminal and hummocky moraines. Glaciers were 1.4 to 12 km long and those from 49 cirques merged to form a broad 75 km<sup>2</sup> piedmont glacier in the Namaras Valley, up to 400 m thick. A thorough analysis of morphometry of the 98 Geyik cirques, using the revised Automated Cirque Metric Extraction version 2 (ACME2) toolbox, shows that they are relatively small, with limited widths: the median length/width ratio of 1.29 is unusually high. With size, length and width increase faster than depth, demonstrating strong static allometry. Maximum slope averages 59°, minimum 3.3° and axial 25°. A combination of low hypsometric integral, high axial profile closure and high axial height-length integral is proposed as a measure of cirque development.</div><div>The main summits are on sharp ridges on cirque crests, showing that they have been lowered by glacial erosion (by cirque development). Glaciation was strongly asymmetric, with cirque vector mean aspect between northeast and north-northeast. This shows the dominance of solar radiation effects, with some modification from westerly winds. Glacier palaeo- Equilibrium Line Altitudes (pELAs) rise northeastwards and cirque floor minimum altitudes (CFAs) rise toward east-northeast, both showing the importance of moist air from the Mediterranean, 38–55 km to the southwest. pELA averages 2208 m above sea level (a.s.l.) (2277 m area-weighted); CFA averages 2234 m. CFA varies mainly with summit altitudes; where related palaeoglaciers are short CFA is somewhat below pELA, but for longer ones it is above. The most likely palaeoclimate to form these glaciers involves a precipitation increase of 53–72 % with a temperature fall of 8 °C compared with present-day. The cirques formed under similar or less severe conditions.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the effect of two-direction seasonal flows on barchans and the origin of occluded dunes 论双向季节性水流对巴丘的影响和闭塞沙丘的起源

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-30 DOI: 10.1016/j.geomorph.2024.109488

We inquire into the morphodynamics of barchans under seasonal flows. For that, we carried out grain-scale numerical computations of a subaqueous barchan exposed to two-directional flows, and we varied the angle and frequency of oscillations. We show that when the frequency is lower than the inverse of the characteristic time for barchan formation, the dune adapts to the new flow direction and recovers the barchan shape while losing less grains than under one-directional flow. For higher frequencies, the dune has not enough time for adaptation and becomes more round while losing more grains. For both cases, we show, for the first time, the typical dynamics of grains (trajectories and forces). In particular, the round barchans are similar to the so-called occluded dunes observed on Mars, where seasons have very high frequencies compared to the dune timescale, different from Earth. Our results represent a possible explanation for that shape.

我们对季节性水流作用下的巴坎形态动力学进行了研究。为此，我们对暴露在双向流下的水下沙丘进行了颗粒尺度的数值计算，并改变了振荡的角度和频率。结果表明，当振荡频率低于沙丘形成的特征时间的倒数时，沙丘会适应新的流动方向，恢复沙丘形状，同时比单向流动时损失更少的颗粒。频率越高，沙丘的适应时间越短，变得越圆，同时流失的颗粒也越多。对于这两种情况，我们首次展示了沙粒的典型动态（轨迹和力）。特别是，圆形沙丘类似于在火星上观测到的所谓闭塞沙丘，与沙丘的时间尺度相比，火星上的季节具有非常高的频率，这一点与地球不同。我们的研究结果为这种形状提供了可能的解释。

引用次数: 0

Inventory of active rock glaciers and their distribution characteristics on the Qinghai-Tibet Plateau and its adjacent mountainous regions 青藏高原及其毗邻山区活动岩冰川及其分布特征清查

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-29 DOI: 10.1016/j.geomorph.2024.109468

With the global climate change, glaciers on the Qinghai-Tibet Plateau (QTP) and its adjacent mountainous regions are retreating rapidly, leading to an increase in active rock glaciers (ARGs) in front of glaciers. As crucial components of water resources in alpine regions and indicators of permafrost boundaries, ARGs reflect climatic and environmental changes on the QTP and its adjacent mountainous regions. However, the extensive scale of rock glacier development poses a challenge to field investigations and sampling, and manual visual interpretation requires substantial effort. Consequently, research on rock glacier cataloging and distribution characteristics across the entire area is scarce. This study statistically analyzed the geometric characteristics of ARGs using high-resolution GF-2 satellite images. It examined their spatial distribution and relationship with local factors. The findings reveal that 34,717 ARGs, covering an area of approximately 6873.54 km², with an average area of 0.19 ± 0.24 km², a maximum of 0.0012 km², and a minimum of 4.6086 km², were identified primarily in north-facing areas at elevations of 4300–5300 m and slopes of 9°–25°, predominantly in the Karakoram Mountains and the Himalayas. Notably, the largest concentration of ARGs was found on north-facing shady slopes, constituting about 42 % of the total amount, due to less solar radiation and lower near-surface temperatures favorable for interstitial ice preservation. This research enriches the foundational data on ARG distribution across the QTP and its adjacent mountainous regions, offering significant insights into the response mechanisms of rock glacier evolution to environmental changes and their environmental and engineering impacts.

随着全球气候变化，青藏高原及其毗邻山区的冰川迅速后退，导致冰川前缘的活动石冰川（ARGs）增多。作为高寒地区水资源的重要组成部分和永久冻土边界的指标，活动岩冰川反映了青藏高原及其毗邻山区的气候和环境变化。然而，岩冰川发育规模巨大，给实地调查和取样带来了挑战，而且人工目测判读也需要耗费大量精力。因此，有关整个地区岩冰川编目和分布特征的研究很少。本研究利用高分辨率的 GF-2 卫星图像对 ARGs 的几何特征进行了统计分析。研究还考察了它们的空间分布以及与当地因素的关系。研究结果表明，共发现 34717 个 ARG，面积约 6873.54 平方公里，平均面积为 0.19 ± 0.24 平方公里，最大面积为 0.0012 平方公里，最小面积为 4.6086 平方公里，主要分布在喀喇昆仑山脉和喜马拉雅山脉海拔 4300-5300 米、坡度 9°-25° 的北向地区。值得注意的是，由于太阳辐射较少，近地表温度较低，有利于间隙冰的保存，北向阴坡上的 ARG 最为集中，约占总量的 42%。这项研究丰富了QTP及其邻近山区ARG分布的基础数据，为了解岩冰川演化对环境变化的响应机制及其对环境和工程的影响提供了重要依据。

{"title":"Inventory of active rock glaciers and their distribution characteristics on the Qinghai-Tibet Plateau and its adjacent mountainous regions","authors":"","doi":"10.1016/j.geomorph.2024.109468","DOIUrl":"10.1016/j.geomorph.2024.109468","url":null,"abstract":"<div><div>With the global climate change, glaciers on the Qinghai-Tibet Plateau (QTP) and its adjacent mountainous regions are retreating rapidly, leading to an increase in active rock glaciers (ARGs) in front of glaciers. As crucial components of water resources in alpine regions and indicators of permafrost boundaries, ARGs reflect climatic and environmental changes on the QTP and its adjacent mountainous regions. However, the extensive scale of rock glacier development poses a challenge to field investigations and sampling, and manual visual interpretation requires substantial effort. Consequently, research on rock glacier cataloging and distribution characteristics across the entire area is scarce. This study statistically analyzed the geometric characteristics of ARGs using high-resolution GF-2 satellite images. It examined their spatial distribution and relationship with local factors. The findings reveal that 34,717 ARGs, covering an area of approximately 6873.54 km<sup>2</sup>, with an average area of 0.19 ± 0.24 km<sup>2</sup>, a maximum of 0.0012 km<sup>2</sup>, and a minimum of 4.6086 km<sup>2</sup>, were identified primarily in north-facing areas at elevations of 4300–5300 m and slopes of 9°–25°, predominantly in the Karakoram Mountains and the Himalayas. Notably, the largest concentration of ARGs was found on north-facing shady slopes, constituting about 42 % of the total amount, due to less solar radiation and lower near-surface temperatures favorable for interstitial ice preservation. This research enriches the foundational data on ARG distribution across the QTP and its adjacent mountainous regions, offering significant insights into the response mechanisms of rock glacier evolution to environmental changes and their environmental and engineering impacts.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oceanic geodiversity along back-arc spreading centers reveals analogies with mid-ocean ridges 沿弧后扩张中心的海洋地质多样性揭示了与大洋中脊的相似性

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2024-10-29 DOI: 10.1016/j.geomorph.2024.109466

Oceanic geodiversity provides essential information on the dynamics of the Earth. Here, we focus on the geodiversity of three oceanic back-arc spreading centers: the Mariana Spreading Center, the Central-Southern Lau Basin spreading centers, and the East Scotia Ridge. We defined a method to identify their axial zones, obtaining spreading center depths along the basins. Results improve global plate boundary models and morphology variations, revealing that the average depths along the Mariana, East Scotia, and Lau Basin spreading ridges are 4.5, 3.5, and 2 km, respectively. We also measured new spreading rates based on five magnetic profiles crossing the three back-arc spreading centers, contributing to plate kinematic models. Furthermore, we computed subduction rates, including hinge velocities along the Mariana, South Sandwich, and Tonga Subductions, to understand the existing interactions between the subducting slab hinge motion and the kinematics of their related back-arc spreading centers. Our bathymetric, magnetic, and kinematic data show several differences among the Mariana, the East Scotia, and the Lau spreading centers, stressing the oceanic geodiversity in a similar geodynamic context. Our results also suggest a strong correlation between axial depth and full spreading rates along the back-arc spreading centers, a geological correspondence that allows a similar description of these divergent plate boundaries within the mid-ocean ridge classification. Finally, we show how hinge kinematics affects the relationship between convergence along subduction zones and back-arc spreading rates. All our findings contribute to understand how the oceanic geodiversity is directly related to geodynamic processes, increasing the knowledge of global tectonics.

海洋地质多样性提供了有关地球动力学的重要信息。在此，我们重点研究了三个大洋弧后扩张中心的地质多样性：马里亚纳扩张中心、中南劳盆地扩张中心和东斯科舍海脊。我们定义了一种识别其轴向区域的方法，获得了沿盆地的扩张中心深度。结果改进了全球板块边界模型和形态变化，揭示了马里亚纳海脊、东斯科舍海脊和劳盆地扩张脊的平均深度分别为 4.5、3.5 和 2 公里。我们还根据穿越三个弧后扩张中心的五条磁剖面测算出新的扩张速率，为板块运动学模型做出了贡献。此外，我们还计算了俯冲速率，包括马里亚纳、南桑威奇和汤加俯冲带的铰链速度，以了解俯冲板块铰链运动与其相关后弧扩张中心运动学之间的相互作用。我们的测深、磁力和运动学数据显示了马里亚纳、东斯科舍和劳扩张中心之间的一些差异，强调了类似地球动力学背景下的海洋地球多样性。我们的研究结果还表明，沿后弧扩张中心的轴向深度和全面扩张速率之间存在很强的相关性，这种地质对应关系允许在大洋中脊分类中对这些分歧板块边界进行类似的描述。最后，我们展示了铰链运动学如何影响沿俯冲带的辐合与弧后扩张速率之间的关系。我们的所有发现都有助于理解海洋地质多样性如何与地球动力学过程直接相关，从而增加对全球构造的了解。

{"title":"Oceanic geodiversity along back-arc spreading centers reveals analogies with mid-ocean ridges","authors":"","doi":"10.1016/j.geomorph.2024.109466","DOIUrl":"10.1016/j.geomorph.2024.109466","url":null,"abstract":"<div><div>Oceanic geodiversity provides essential information on the dynamics of the Earth. Here, we focus on the geodiversity of three oceanic back-arc spreading centers: the Mariana Spreading Center, the Central-Southern Lau Basin spreading centers, and the East Scotia Ridge. We defined a method to identify their axial zones, obtaining spreading center depths along the basins. Results improve global plate boundary models and morphology variations, revealing that the average depths along the Mariana, East Scotia, and Lau Basin spreading ridges are 4.5, 3.5, and 2 km, respectively. We also measured new spreading rates based on five magnetic profiles crossing the three back-arc spreading centers, contributing to plate kinematic models. Furthermore, we computed subduction rates, including hinge velocities along the Mariana, South Sandwich, and Tonga Subductions, to understand the existing interactions between the subducting slab hinge motion and the kinematics of their related back-arc spreading centers. Our bathymetric, magnetic, and kinematic data show several differences among the Mariana, the East Scotia, and the Lau spreading centers, stressing the oceanic geodiversity in a similar geodynamic context. Our results also suggest a strong correlation between axial depth and full spreading rates along the back-arc spreading centers, a geological correspondence that allows a similar description of these divergent plate boundaries within the mid-ocean ridge classification. Finally, we show how hinge kinematics affects the relationship between convergence along subduction zones and back-arc spreading rates. All our findings contribute to understand how the oceanic geodiversity is directly related to geodynamic processes, increasing the knowledge of global tectonics.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0