The hot fluids emanating from hot vents tends to chemically alter the magnetic minerals and thus destroy any magnetic signal. The TAG hydrothermal site on the Mid-Atlantic ridge is one place where we have documented the presence of a magnetic low over the vent site. TAG magnetics Juan de Fuca Ridge, North East Pacific Ocean Juan de Fuca Ridge, North East Pacific Magnetic surveying of a steep scarp that exposes a cross-section of ocean crust was conducted in 1995 at the Blanco Fracture Zone which marks the southern boundary of the Juan de Fuca plate in the northeast Pacific. An important problem in marine magnetism concerns the vertical structure of oceanic crust and what part of the crust is responsible for creating magnetic anomalies that are measured at the sea surface. Click below for more details on these results.
New lava is typically very magnetic and creates a strong magnetic field signal when first formed.
Click below for more details on these results. There has long been a debate over whether the Jurassic period was a time of no magnetic reversals like the Cretaceous quiet zone or a time of very rapid reversal of simply a time when the earths field was weaker. Few magnetic measurements have been able to determine which of these scenarios is correct with any accuracy. Click below for more details on these results.