Detecting the magnetic characteristics of submarine volcanic area off the coast of northern Taiwan

Taiwan Island, the product of an active mountain building, is deduced from the oblique collision between the Eurasian and the Philippine Sea plate, and its northern part and offshore region are under post-collision collapse. We have collected the magnetic data to combine and compile a map of regional magnetic anomalies for investigation of the volcanic and igneous arrangement over this area off the coast of northern Taiwan, where a series of submarine volcanoes and igneous rock isles are rooted. Generally, a magnetic high largely dominates the area of most submarine volcanoes and extends eastward, while the adjacent area to the north is lower. To better understand the magnetic features for the submarine volcanic area, several magnetic methods are used, such as the inversion with an equivalent magnetic layer thickness for the magnetization distribution; the enhanced analytic signal technique for evaluating the magnetic source strength distribution; using the tilt angle of the total horizontal gradient and the tilt angle of the analytic signal amplitude for detecting the source edges. Amongst the area, a small part segment with dense survey line that may provide a more detailed resolution result.