Liquefaction Induced during the 2010–2011 Canterbury, New Zealand, Earthquake Sequence and Lessons Learned for the Study of Paleoliquefaction Features
Liquefaction Induced during the 2010–2011 Canterbury, New Zealand, Earthquake Sequence and Lessons Learned for the Study of Paleoliquefaction Features
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2010-2011年新西兰坎特伯雷地震序列引起的液化以及古液化特征研究的经验教训
DOI：
10.1785/0220170073
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发表时间：
2017
影响因子：
3.3
通讯作者：
Caroline M. Hardwick
中科院分区：
文献类型：
--
作者：
M. Tuttle;P. Villamor;P. Almond;S. Bastin;M. Bucci;R. Langridge;K. Clark;Caroline M. Hardwick
摘要2010-2011年新西兰南岛基督城及周边地区发生的坎特伯雷系列特大至中等地震导致部分地区液化。收集到的关于这种反复液化的详细信息为研究古液化特征和引起它们的古地震提供了重要的经验教训。坎特伯雷的案例表明，在断层破裂不一定传播到地表、可能被后来的沉积所掩盖或难以识别的地区，液化特征是强烈地面震动的重要指标。比较坎特伯雷序列中2010年达菲尔德7.1级和2011年基督城6.2级地震产生的液化场，突出了场地条件对液化特征地理分布的影响，并强调了在使用古液化特征解释震源区和震级时，需要考虑沉积物的液化敏感性和地下水位深度。古地震在达菲尔德和基督城地震期间形成的液化特征的震中距离和大小证实并进一步限制了用于估计震源区和古地震震级的经验关系。复合砂击的形成是由坎特伯雷地震期间反复液化产生的多个砂-粉砂偶层组成的，支持了先前对美国中部和西部复合砂击的解释。此外，在2010-2011年坎特伯雷地震期间形成的砂吹挖掘中发现的古液化特征表明，现代液化的地点是古液化研究的主要目标。液化特征形成和保存的沉积环境有助于指导古液化特征的搜索。需要从一个地区的许多站点的信息来开发过去的液化事件的年表，以确定其液化场，并估计震源区和古地震的震级。
ABSTRACT Very large to moderate earthquakes in the 2010–2011 Canterbury sequence induced liquefaction in parts of Christchurch city and the surrounding region on the South Island of New Zealand. Detailed information gathered about this case of recurrent liquefaction offers important lessons for the study of paleoliquefaction features and the paleoearthquakes that caused them. The Canterbury case demonstrates that liquefaction features are important indicators of strong ground shaking in regions where fault ruptures do not necessarily propagate to the surface, may be masked by later sedimentation, or are otherwise difficult to recognize. Comparison of the liquefaction fields produced by the 2010 M 7.1 Darfield and 2011 M 6.2 Christchurch earthquakes in the Canterbury sequence highlights the influence of site conditions on the geographical distribution of liquefaction features and underscores the need to consider liquefaction susceptibility of sediment and depth of the water table when using paleoliquefaction features to interpret the source area and magnitude of paleoearthquakes. The epicentral distance and size of liquefaction features that formed during the Darfield and Christchurch earthquakes corroborate and further constrain empirical relations used to estimate source areas and magnitudes of paleoearthquakes. Formation of compound sand blows, composed of multiple sand–silt couplets resulting from repeated liquefaction during the Canterbury earthquakes, supports previous interpretations of compound sand blows in the central and western United States. In addition, paleoliquefaction features found in excavations of sand blows that formed during the 2010–2011 Canterbury earthquakes indicate that sites of modern liquefaction are prime targets for paleoliquefaction studies. The depositional environments where liquefaction features form and are preserved help to guide searches for paleoliquefaction features. Information from many sites across a region is needed to develop a chronology of past liquefaction events, to define their liquefaction fields, and to estimate the source areas and magnitudes of paleoearthquakes.