A preliminary magnetic anomaly study of the Nieuwerkerk Seamount, Banda Sea, Indonesia

Abstract The Nieuwerkerk seamount has been identified in the Banda Sea since the 1930s by Dutch researchers through the Snellius Expedition. However, the physical description of the seamount and its relation to the surrounding seafloor features has not been discussed due to the lack of geophysical data in the area. This study addresses those issues by examining the shipboard magnetic anomalies acquired during the Jalacitra II-2022 “Banda” Expedition. The result indicates two possible magmatic flows, with the reduced-to-equator magnetic anomaly of around -120 nT and -30 nT at the main and secondary summits, respectively. No magnetic anomaly is identified at the ridge east of the seamount, indicating the absence of structure or magmatic rocks. An extreme magnetic anomaly contrast of up to 145 nT is indicated at the southern foot of the seamount, striking ENE-WSW. These magnetic discontinuities are possibly depicting strike-slip faults, which are also found at the three other smaller seamounts southwest of Nieuwerkerk. These preliminary physical descriptions are key to opening up a discussion on the structure and activities of the Nieuwerkerk seamount and its relationship with the surrounding seafloor features.