Reconstructions of the past behavior of the geomagnetic field critically depend on the magnetic signal stored in extrusive igneous rocks. These rocks record the Earth's magnetic field when they cool and retain this magnetization on geological timescales. In rugged volcanic terrain, however, the magnetic signal arising from the underlying flows may influence the ambient magnetic field as recorded by newly formed flows on top. To measure these local anomalies in the Earth's magnetic field directly we developed a low-cost field magnetometer based on a fluxgate sensor. To improve the accuracy of the obtained paleomagnetic vector and user-friendliness of the device, we combined this fluxgate sensor with tilt and GPS sensors to rotate the measured magnetic vector to true north, east, and down. The data acquisition is done using a ruggedized laptop, and data are immediately available for first-order interpretation. The first measurements done on Mt. Etna show local variations in the ambient magnetic field that are larger than expected and illustrate both the accuracy (certainly <0.5^∘ in paleomagnetic direction) and potential of our new device.

中文翻译：

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一种用于测量火山地形中局部磁异常的低成本设备

地磁场过去行为的重建主要取决于存储在挤压火成岩中的磁信号。这些岩石在冷却时记录地球的磁场，并在地质时标上保留这种磁化强度。但是，在崎vol的火山地形中，由下伏流产生的磁信号可能会影响环境磁场，如顶部新形成的流所记录的那样。为了直接测量地球磁场中的这些局部异常，我们开发了一种基于磁通门传感器的低成本磁场磁力计。为了提高所获得的古磁矢量的准确性和设备的用户友好性，我们将此磁通门传感器与倾斜传感器和GPS传感器结合使用，以将测得的磁矢量旋转到真实的北，东和下。数据采集​​使用坚固耐用的笔记本电脑完成，数据可立即用于一阶解释。首次在Mt. Etna显示环境磁场中的局部变化大于预期，并说明了两者的准确性（当然在古^磁方向上<0.5））和我们新设备的电势。