ERTH 2415 Lecture Notes - Lecture 1: Space Weather, Ionosphere, Electromagnetic Induction

• School: Carleton University
• Department: Earth Sciences
• Course: ERTH 2415
• Professor: Jason Mah

Document Summary

Farada(cid:455)"s la(cid:449) magnetic fields variations induce a current in a medium and then this current creates its own magnetic field. Variatio(cid:374)s i(cid:374) the earth"s (cid:373)ag(cid:374)eti(cid:272) field i(cid:374)du(cid:272)e ele(cid:272)tri(cid:272)al (cid:894)(cid:862)telluri(cid:272)(cid:863)(cid:895) (cid:272)urre(cid:374)ts. Electromagnetic surveying can be done from a helicopter or can also be ground based. We create our own magnetic field and this is a control experiment. By this experiment we estimate the depth, shape and electrical conductivity of subsurface ore bodies, metallic bodies are more conductive then sedimentary rocks. E(cid:454)tre(cid:373)e (cid:448)ariatio(cid:374)s of the earth"s (cid:373)ag(cid:374)eti(cid:272) field (cid:272)a(cid:374) ha(cid:448)e a sig(cid:374)ifi(cid:272)a(cid:374)t effe(cid:272)t o(cid:374) te(cid:272)h(cid:374)ologi(cid:272)al systems. Magnetometer a device that records the super position of internal geomagnetic field (earth"s (cid:272)ore(cid:895) + e(cid:454)ter(cid:374)al geo(cid:373)ag(cid:374)eti(cid:272) field (cid:894)(cid:373)ag(cid:374)eto/io(cid:374)osphere(cid:895) Differentiation of the earth denser material gradually migrated to the centre of the earth, density increases as we move towards the centre. Internal geomagnetic field is created due to the movement of liquid in the outer core. This field resembles the field of a bar of magnet.