Earthquake induced rotational ground motions

几十年来，理论地震学家一直认为，除了平移和应变之外，旋转也应该被测量。到目前为止的问题是，仪器--特别是基于机械的传感器--没有为宽带地震学提供所需的分辨率。在之前的一项研究中，我们首次证明了基于环形激光技术的光学传感器能够测量地震引起的旋转运动，正如理论所预期的那样。此外，我们可以证明，旋转和平移的并置记录包含标准三分量地震仪记录中不存在的附加信息。这表明地震学有了一个值得系统探索的新的观测对象。在这个项目中，我们建议(1)对新的观测数据进行处理和建模，并规划在波传播、地震破裂和地震工程问题中的潜在应用领域；(2)制定标准和基础设施，以便能够传播旋转观测数据，并与其他地震波形数据一起有效地使用；(3)利用低分辨率移动旋转传感器进行测试，并测试它们是否适合进行实地研究(例如，靠近震源或火山)。

Theoretical seismologists have argued for decades that - in addition to translations and strains - rotations should also be measured. The problem so far had been that instruments - particularly mechanically based sensors - did not provide the required resolution for broadband seismology. In a previous study we could demonstrate for the first time that optical sensors based on ring laser technology are capable of measuring seismically induced rotational motions as expected from theory. In addition, we could show that collocated recordings of rotations and translations contain additional information not present in standard three-component seismometer recordings. This suggests that seismology has a new observable that is worth exploring systematically. In this project we propose (1) to process and model the novel observations and map out potential fields of applications in wave propagation, earthquake rupture, and earthquake engineering problems; (2) to develop standards and infrastructure with which rotational observations can be disseminated and used efficiently in line with other seismological waveform data; and (3) to carry out tests with low -resolution mobile rotation sensors and test their fitness for field studies (e.g., close to seismic sources or at volcanoes).