The magnetic anomalies represented on this map originate primarily in igneous and metamorphic rocks, in the Earth’s crust and possibly, uppermost mantle. Magnetic anomalies represent an estimate ...

Its software uses your phone’s built-in compass and measures the anomalies ... magnetic observations differ depending on how we move through these fields, such magnetic signatures can be used as ...

is called the South Atlantic Anomaly. These developments have led to speculations that we may be heading for a polarity reversal. Map of intensity of magnetic Earth field in 2015. Source: ...