what is the magnetic field of the earth
Earth's magnetic field The intensity of the field is often measured in gauss (G), but is generally reported in nanoteslas (nT), with 1 G = 100,000 nT. A nanotesla is also referred to as a gamma (γ).[13] The tesla is the SI unit of the magnetic field, B. The Earth's field ranges between approximately 25,000 and 65,000 nT (0.25–0.65 G). By comparison, a strong refrigerator magnet has a field of about 10,000,000 nanoteslas (100 G).[14]
Outer core Estimates for the temperature of the outer core are about 3,000–4,500 K (2,730–4,230 °C; 4,940–7,640 °F) in its outer regions and 4,000–8,000 K (3,730–7,730 °C; 6,740–13,940 °F) near the inner core.[4] Evidence for a fluid outer core includes from seismology which shows that seismic shear-waves are not transmitted through the outer core[5] Because of its high temperature, modeling work has shown that the outer core is a low viscosity fluid that convects turbulently.[4] Eddy currents in the nickel iron fluid of the outer core are believed to influence the Earth's magnetic field. The average magnetic field strength in the Earth's outer core was measured to be 2.5 millitesla, 50 times stronger than the magnetic field at the surface.[6][7] The outer core is not under enough pressure to be solid, so it is liquid even though it has a composition similar to the inner core. Sulfur and oxygen could be present in the outer core.[8]