Relating the long-term and short-term vertical deformation across a transect of the forearc in the central Mexican subduction zone
Relating the long-term and short-term vertical deformation across a transect of the forearc in the central Mexican subduction zone
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墨西哥中部俯冲带弧前横断面的长期和短期垂直变形的关系
DOI：
10.1130/ges01446.1
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发表时间：
2018
期刊：
影响因子：
2.5
通讯作者：
C. Johnson
中科院分区：
文献类型：
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作者：
M. Ramírez;K. Gaidzik;S. Forman;V. Kostoglodov;R. Bürgmann;C. Johnson
作者：Ramirez-Herrera，MT；盖兹克，K；福尔曼，S；科斯托格洛多夫，V；伯格曼，R；约翰逊，CW |摘要：© 2018 作者。地震周期变形包括地震破裂、震间应变和瞬态慢滑移事件，其空间尺度从几分之一米到数千公里不等。同样，时间尺度的范围从地震破裂期间的几秒钟到地震之间数千年的应变积累。我们讨论了与格雷罗地震间隙墨西哥中部俯冲前弧横断面的缓慢和快速地壳变形相关的垂直地壳变形的结果，其中科科斯板块向北美板块俯冲。俯冲带的这个部分的特点是平坦的板片几何形状，具有板片急剧弯曲-不弯曲的区域、不规则分布的地震活动以及异常大的慢滑动事件。我们利用弧前横断面的河网、地形、地貌特征和形态测量来评估第四纪地壳变形。帕帕加约排水网络显示，弧前自新生代晚期（约 25 Ma）以来一直在抬升，并且自全新世开始以来抬升率有所增加。隆起并不均匀，而是呈现远离海岸增加的趋势。这种垂直变形受到俯冲过程的强烈影响。因此，帕帕加约河网受到全新世地震周期过程的强烈控制。对于流域南段来说尤其如此，那里东西走向的具有垂直分量的左旋走滑断层抵消了主河的河道。这些断层是墨西哥俯冲带斜板块汇聚的一部分。我们通过光激发光测量了一系列阶地的高度和测年石英提取物，并计算了每年 0.5 至 4.9 毫米的长期抬升率。我们讨论了弧前地形、断层和长期地壳变形与科科斯板块几何形状、慢滑动事件的分布和地震周期变形的关联。
Author(s): Ramirez-Herrera, MT; Gaidzik, K; Forman, S; Kostoglodov, V; Burgmann, R; Johnson, CW | Abstract: © 2018 The Authors. Earthquake-cycle deformation, which includes earthquake ruptures, interseismic strain, and transient slow slip events, spans spatial scales ranging from fractions of a meter to thousands of kilometers. Similarly, temporal scales range from seconds during an earthquake rupture to thousands of years of strain accumulation between earthquakes. We discuss results regarding the vertical crustal deformation associated with both slow and rapid crustal deformation across a transect of the central Mexican subduction forearc in the Guerrero seismic gap, where the Cocos plate underthrusts the North America plate. This sector of the subduction zone is characterized by a flat-slab geometry with zones of sharp bending-unbending of the slab, irregularly distributed seismicity, and exceptionally large slow slip events. We used the river network, topography, geomorphic features, and morphometry on a transect across the forearc to assess Quaternary crustal deformation. The Papagayo drainage network shows that the forearc has been uplifted since the late Cenozoic (~25 Ma), and that rates of uplift increased since the beginning of the Holocene. Uplift is not homogeneous but shows a trend of increase away from the coast. This vertical deformation is strongly influenced by subduction processes. Thus, the Papagayo River network is strongly controlled by Holocene earthquake cycle processes. This is particularly true for the southern section of the drainage basin, where E-W-striking left-lateral strike-slip faults with a vertical component offset the course of the main river. These faults are accommodating part of the oblique plate convergence at the Mexican subduction zone. We measured the height of a series of terraces and dated quartz extracts by optically stimulated luminescence, and we calculated long-term rates of uplift ranging from 0.5 to 4.9 mm/yr. We discuss associations of forearc topography, faults, and long-term crustal deformation with the Cocos slab geometry, distribution of slow slip events, and earthquake-cycle deformation.
影响因子：
18.3
作者：
Wesson;Melnick;Cisternas;Moreno
通讯作者：
Moreno