Taiwan Bank, or Taiwan Shoal, is an ocean bank located on the seabed at the southern end of the Taiwan Strait. It is to the southwest of Penghu Islands and to the east of the Nanpeng Islands.
Taiwan Bank is a residual sedimentation of continental shelf.[1] The undersea terrain of the Taiwan Strait used to be a valley, and had been constantly accumulating soil and sand from both sides since the Pliocene until the Holocene, when sea levels rose and remains of sands beneath the sea become oceanic bank.
The Kuroshio Current and typhoon waves help push sands on the seabed to the north, but are blocked by ancient volcanic rocks and beach rocks, thus while the sands are constantly moving, they would not be transported to weaker current areas further away. On the other hand, south-flowing currents and waves caused by northeasterly trade wind transport sand on the bank to the south. These forces in both directions cancel out each other's reached relative stability and equilibrium, forming sand waves and dunes under the sea.[2]
Some academics have hypothesized that during the Little Ice Age when the sea level dropped, Taiwan Bank might have been inhabitable by humans. Thus, they think the island marked Dongning on the map Kunyu Wanguo Quantu published in year 1602 could in fact be Taiwan Bank instead of the Taiwan Island.