FUNDAMENTALS OF RIDGE CREST TOPOGRAPHY
FUNDAMENTALS OF RIDGE CREST TOPOGRAPHY
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DOI：
10.1016/0012-821x(74)90180-0
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发表时间：
1974-01-01
影响因子：
5.3
通讯作者：
LISTER, CRB
中科院分区：
文献类型：
--
作者：
DAVIS, EE;LISTER, CRB
海底深度和年龄的平方根之间的线性关系已被发现的海洋岩石圈扩张从洋中脊。作为热收缩岩石圈的年龄的函数的深度的渐近解预测的线性依赖的深度ontwith的比例涉及初始岩石圈温度，热扩散率，均衡膨胀系数平均，包括任何温度相关的相变。经验性的深度观测，当绘制成年龄平方根的函数时，很好地证实了这一预测，但是梯度ht，沿着海脊在精细尺度上有变化（在200公里上可达20%）。这意味着在同一尺度上的收缩参数的基本变化，最有可能的成分来源。一个更完整的冷却模型的细节附近的脊顶，包括不同的热参数比地幔的地壳，预测约0.2公里以下的简化模型的脊高。从东南太平洋的个人配置文件没有显示这样的脊偏差，它的结论是，通过快速冷却新的地壳，热液循环可能会删除任何影响的地壳，这将是在地形中看到的岩石圈完全通过传导冷却。深度的平直度与较老的海洋数据（到8000万年）排除任何浅于100 km的基底等温边界。
A linear relationship between the sea floor depth and the square root of age has been found for ocean lithosphere spreading from mid-ocean ridges. The asymptotic solution of depth as a function of age for the thermally contracting lithosphere predicts a linear dependence of depth ontwith a proportionality involving the initial lithosphere temperature, the thermal diffusivity, and the isostatic expansion coefficient averaged to include any temperature dependent phase changes. Empirical depth observations, when plotted as a function of the square root of age, bear out this prediction well, but there is a variation in the gradient,ht, along the ridge on a fine scale (up to 20% over 200 km). This implies a fundamental variation of the contraction parameter over the same scale, most probably of compositional origin. Details of a more complete cooling model near the ridge crest, including a crust of different thermal parameters than those of the mantle, predict a crestal height about 0.2 km below that of the simplified model. Individual profiles from the southeast Pacific show no such crestal deviation, and it is concluded that by quickly cooling the new crust, hydrothermal circulation may remove any effects of the crust which would be seen in the topography of a lithosphere cooled totally by conduction. The straightness of depth versustfor older ocean data (to 80 m.y.) precludes any basal isothermal boundary shallower than 100 km.