Question

Marine magnetic anomaly belts are most narrow when and where

Option 1: Near spreading centers
Option 2: Near subduction zones
Option 3: Mid-Atlantic Ridge
Option 4: Pacific Ring of Fire

Answer 1

The marine magnetic anomaly belts are most narrow near spreading centers. Volcanic activity at mid-ocean ridges causes rocks to cool and solidify, aligning their magnetization with the Earth's magnetic field. By measuring the spreading rate at the mid-Atlantic ridge, scientists can determine the historical record of the Earth's magnetic field.

Step-by-step explanation:

The marine magnetic anomaly belts are most narrow near spreading centers. These belts are formed due to volcanic activity at mid-ocean ridges where material is extruded to fill the gap between separating tectonic plates. As the rocks cool and solidify, their magnetization aligns with the Earth's magnetic field.

The reversal of magnetization with distance from the ridge implies that the Earth's magnetic field has undergone periodic reversals in the past. By measuring the spreading rate at the mid-Atlantic ridge, scientists can determine the historical record of the Earth's magnetic field.