麻豆直播

This was discussed by Prof. Satria Bijaksana in a discussion themed 鈥淗ow Earth鈥檚 Magnetic Field Change and the Impact to Humankind鈥� held by Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering of 麻豆直播, on Wednesday (16/01/2019) at Energy Building Hall, 麻豆直播 Campus.

According to Prof. Satria, what the researchers said on the journal reveals the result of their observation, which shows Earth鈥檚 magnetic fast movement. 鈥淭hat brings forward two concerns of the research. Practically, navigation maps should be updated immediately, and they should think about the cause of magnetic changes,鈥� said Prof. Satria.

World Magnetic Model is used on all navigation systems. The model is updated once every five years. However, because magnetic field moves too fast, update is required even faster. However, updating maps fast will take long processes because it requires data from all over the world.

*Prof. Satria Bijaksana from Global Geophysics Research Group of 麻豆直播 (Doc. Humas 麻豆直播)

鈥淰ariations regarding Earth鈥檚 magnetic field need to be known but not to be worried because Indonesia stands far away from magnetic poles and thus relatively unaffected,鈥� he said. The biggest impact of magnetic field change will affect North Pole because navigation direction shifts.

A Glimpse at Magnetic Field

On the discussion, Prof. Satria explained that Earth鈥檚 magnetic field has been around for at least 4.2 billion years ago. Earth鈥檚 magnetic field is beneficial in determining direction on compass/navigation. In Indonesia, the first measure to Earth鈥檚 magnetic field intensity was conducted by de Rossell on 9 October 1792 in Surabaya.

鈥淓arth鈥檚 magnetic field is basically very weak, undetectable with human sense. Basically it has dipole shape with two poles referred to as north pole and south pole. Direction and intensity of the field varies, depending usually on latitude position,鈥� he said.

Currently, Earth鈥檚 magnetic field is weakening. But it is highly probable to strengthen again. 鈥淭he trend is currently weakening, but do not worry because it is a common weakening. Seen from the track record, it used to weaken and strengthen,鈥� he said.

The magnetic field is generated by electric current, caused by the movement of conductive material on the outer layer of Earth鈥檚 core. The Earth becomes a giant electromagnetic generator. This is commonly referred to as Dynamo Theory. Even though it is simple principally, details such as the property, material on the outer core, fluid movement mechanism, etc remain uncertain.

Prof. Satria said that, historically, Earth鈥檚 magnetic field has never reach nil. However, magnetic field reverse used to happen. The trigger could be meteor collision, the fall of continental plate onto the mantle, or the presence of new mental plume on the boundary between Earth鈥檚 core and mantle.

He explained how Earth鈥檚 magnetic field has several interesting aspects, such as how Earth鈥檚 magnetic field does not coincide with the axis of Earth鈥檚 rotation, not even passing Earth鈥檚 center. Earth鈥檚 Magnetic field is still measurable for 7 up to 10 times Earth鈥檚 diameter. Hence, satellite on outer space could still be controlled using Earth鈥檚 magnetic field.

Magnetic Field and Solar Wind

Earth鈥檚 magnetic field protects the Earth from solar wind, an activity where the Sun generates radiation of particles, which contains mostly of hot protons and high-energy from the Sun. According to Prof Satria, this should be a concern.

Magnetic field layer that covers the Earth is called magnetosphere. There are several conditions that occur to magnetosphere when interacting with solar wind. If the solar wind is weak, the magnetosphere expands, and when solar wind strengthens, the magnetosphere shrinks. The period when solar wind鈥檚 intensity rise is called geomagnetic storm. The storm could occur during coronal mass ejection (CME) eruption on the Sun which release shockwaves onto the solar system.

This magnetic storm could cause disturbances such as telegraph network interference in 1859, Electricity network outage in Canada in 1989, disturbance to one third of NASA鈥檚 satellite in 2003. 鈥淲ith our dependence to satellite telecommunication and communication, we have to realize that there may be interference due to interaction of the Earth鈥檚 magnetic field with solar wind,鈥� he said.