Location of the Dip Equator over Peninsular India

Abstract

The dip equator runs over only the landmass of South America, Central Africa and peninsular India apart from a small section further east of India. A ground magnetic survey was conducted to determine the absolute values of both (I) and (Z) in the southern most part of peninsular India, to know the location and migratory nature of the dip equator for the epoch 2003.7. Though no trace of dip equator was found on the said landmass even after the last possible site at Kanyakumari, based on the data of ground magnetic survey, attempts are made here to trace it statistically. A well-defined southward migration over a period of last three and a half decades is still evident.The location of the dip equator between 76°E and 78°E (Indian sector) and its migratory nature in this sector are highlighted by the ground survey data comparing with the IGRF model data along with the nature of secular trends of the vertical field from stations in the equatorial region of India.