Inversion of GEOHALO aerogravimetry to infer ocean bottom topography: application to the Tyrrhenian, Ionian and Adriatic seas
Inversion of GEOHALO aerogravimetry to infer ocean bottom topography: application to the Tyrrhenian, Ionian and Adriatic seas
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DOI：
10.1093/gji/ggy456
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发表时间：
2018-11
影响因子：
2.8
通讯作者：
T. Schaller;M. Scheinert;Franz Barthelmes-;C. Förste
中科院分区：
文献类型：
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作者：
T. Schaller;M. Scheinert;Franz Barthelmes-;C. Förste
详细而精确的海底地形知识在许多地球科学和海洋学应用中是必不可少的。船载回声测深是唯一的直接测深方法。然而，即使在应用这种技术几十年后，也只能覆盖全球海洋的一小部分。另外，重力数据反演是推断海底地形的可行方法，因为重力场在短到中波长处与地形相关。全球范围内的重力场观测数据由GOCE、GRACE和GRACE-FO等专用卫星任务提供，在海洋上空则由卫星测高提供。区域和地方测量通过地基、船载和航空重力测量实现。欧洲首次使用喷气式飞机进行航空重力测量。在2012年6月对意大利以及第勒尼安海、爱奥尼亚海和亚得里亚海进行的GEOHALO飞行活动中，德国研究飞机HALO携带了一整套大地测量-地球物理仪器，包括重力仪。对德国地球科学研究中心CHEKAN-AM仪器获得的重力数据进行了仔细处理，使其精度达到了mGal水平。随后，帕克-奥尔登堡反演被应用于预测海底地形沿着飞越海洋的GEOHALO剖面。为了约束反演中的参数空间，我们使用了Crust1.0模型。最后，将所得结果与通用海洋等深线图进行了比较，以评估该方法的性能。我们的研究表明，喷气式飞机上的航空重力测量能够为区域地球科学研究提供有价值的数据。
A detailed and precise knowledge of ocean bottom topography is essential in many geoscientific and oceanographic applications. Shipborne echo sounding provides the only direct bathymetric method. However, even after decades of applying this technique only a fraction of the global ocean could be covered. Alternatively, gravity data inversion is a feasible method to infer ocean bottom topography since the gravity field correlates with topography at short to medium wavelengths. Gravity field observables are globally provided by dedicated satellite missions like GOCE, GRACE and GRACE-FO and, over the oceans, by satellite altimetry. Regional and local measurements are realised by means of ground-based, shipborne and airborne gravimetry. For the first time in Europe a jet aircraft was used for airborne gravimetry. During the GEOHALO flight campaign over Italy and the Tyrrhenian, Ionian and Adriatic seas in June 2012, the German research aircraft HALO carried an entire suite of geodetic-geophysical instrumentation, including gravity metres. The careful processing of the gravity data acquired by the CHEKAN-AM instrument of the German Research Centre for Geosciences allowed to achieve an accuracy at the mGal level. Subsequently, the Parker–Oldenburg inversion was applied to predict ocean bottom topography along the GEOHALO profiles flown over the ocean. To constrain the parameter space in the inversion we used the Crust1.0 model. Finally, the obtained results were compared to the General Bathymetric Chart of the Oceans in order to estimate the performance of the method. Our study demonstrates that airborne gravimetry aboard a jet aircraft is capable to provide valuable data for regional geoscientific studies.