Fig. 1
From: Building the second version of the World Digital Magnetic Anomaly Map (WDMAM)

Global map of the Earth’s magnetic anomalies relative to the CM4 main field model for year 1990
From: Building the second version of the World Digital Magnetic Anomaly Map (WDMAM)
Global map of the Earth’s magnetic anomalies relative to the CM4 main field model for year 1990