Distribution of zirconium, hafnium, niobium, and tantalum in the Indian Ocean

Abstract

Zirconium (Zr), hafnium (Hf), niobium (Nb),and tantalum (Ta) are known as high-field strength elements (HFSE) since they form highly charged ions. Because the mole ratios of Zr/Hf and Nb/Ta in seawater change significantly depending on water masses, they are considered to be useful as their tracers. We will report the concentration profiles of the four elements in dissolved (d) and total dissolvable (td) fractions at eleven stations from 40^oE, 62^oS to 86^oE, 17^oN in the Indian Ocean. We will also compare them with our results in the subarctic North Pacific Ocean and previous studies in the Atlantic Ocean.