The Philippine Sea plate is an integral part of the east Asian plate mosaic but its past motions can only be reconstructed from paleomagnetic data. Moreover, because the plate is largely submarine, few fully-oriented paleomagnetic data are available. International Ocean Discovery Program (IODP) Expedition 352 cored at four sites on the Izu-Bonin forearc, penetrating ∼1170 m of forearc igneous crust radiometrically dated at ∼51 Ma. Paleomagnetic measurements on 361 samples produced paleo-inclination data that were used to estimate paleolatitude. Twenty five independent magnetic units give a paleocolatitude of 90.1° ±4.4° (2σ uncertainty), implying a paleolatitude exactly on the equator. Unit variance agrees with global paleosecular variation models, implying that these variations have been properly sampled and averaged. The paleolatitude implies northward drift of ∼28°, which agrees with other Izu-Bonin forearc sites of similar age. A slight difference in northward drift with southern Philippine Sea plate sites is consistent with plate rotation. Certain parts of the cored sections yield samples that were remagnetized to the present geocentric axial dipole inclination after ∼30 Ma, implying a tectonic event of unclear origin.

菲律宾海板块是东亚板块镶嵌的一个组成部分，但它过去的运动只能从古地磁数据中重建。此外，由于该板块主要位于海底，因此很少有完全定向的古地磁数据可用。国际海洋探索计划 (IODP) 远征 352 在伊豆-博宁前弧的四个地点取芯，穿透了约 1170 米的前弧火成岩地壳，辐射测定为约 51 Ma。对 361 个样本的古地磁测量产生了用于估计古纬度的古倾角数据。25 个独立的磁单元给出了 90.1° ±4.4°（2σ 不确定性）的古纬度，这意味着古纬度正好在赤道上。单位方差与全球古长期变化模型一致，这意味着这些变化已被适当地采样和平均。古纬度意味着向北漂移~28°，这与其他类似年龄的伊豆-博宁弧前遗址一致。向北漂移与菲律宾南部海板块位置的轻微差异与板块旋转一致。取芯部分的某些部分产生的样品在 30 Ma 后被重新磁化为目前的地心轴向偶极子倾角，这意味着一个起源不明的构造事件。