SUMMARY

Quasigeoid models can be determined from surface gravity anomalies, so are sensitive to changes in the shape of the topography as well as changes in gravity. Here we present results of forward modelling gravity/quasigeoid changes from synthetic aperture radar data following the 2016 M_w 7.8 Kaikōura earthquake with land uplift of up to 10 m. We assess the impact of the topographic deformation on the reference surface of the New Zealand vertical datum in lieu of costly field gravity field measurements. The most significant modelled gravity and quasigeoid changes are—2.9 mGal and 5–7 mm, respectively. We compare our forward modelled gravity signal to terrestrial gravity observation data and show that differences between the data sets have a standard deviation of ±0.1 mGal. The largest modelled change in the quasigeoid is an order of magnitude smaller than the 57.7 mm estimated precision of the most recently computed NZGeoid model over the Kaikōura region. Modelled quasigeoid changes implied by this particular deformation event are not statistically significant with respect to estimated precision of the New Zealand quasigeoid model.

中文翻译：

---

使用卫星雷达遥感评估2016年Kaikōura地震后新西兰准类星体的时间稳定性

概要

准类地线模型可以从表面重力异常确定，因此对地形形状的变化以及重力的变化都很敏感。在这里，我们从2016年M _w的合成孔径雷达数据中得出重力/准类星体变化的正向建模结果7.8海高浦地震，陆地隆起高达10 m。我们评估了地形变形对新西兰垂直基准面参考表面的影响，以代替昂贵的场重力场测量。最重要的模拟重力和准类星体变化分别为2.9 mGal和5-7 mm。我们将前向建模的重力信号与地面重力观测数据进行了比较，结果表明，数据集之间的差异的标准偏差为±0.1 mGal。拟类星体中最大的模型变化比Kaikōura地区最新计算的NZGeoid模型的估计精度57.7 mm小一个数量级。相对于新西兰拟大地壳模型的估计精度，此特定变形事件所隐含的拟拟类地壳变化在统计上并不显着。