Bri

• The Earth's crust is the outer most layer of the Earth, thicker where there are mountains and thinner on flat surfaces.
• The Earth's crust comprises about 95% igneous and metamorphic rocks, 4% shale, 0.75% sandstone, and 0.25% limestone.
• Oxygen, silicon, aluminum, and iron account for 88.1% of the mass of the Earth's crust, while another 90 elements make up the remaining 11.9%.
• The mantle is the thickest layer of the Earth, divided into two: upper mantle (asthenosphere) and lower mantle.
• Common silicates found in the mantle include olivine, garnet, and pyroxene.
• The other major type of rock found in the mantle is magnesium oxide.
• Other mantle elements include iron, aluminum, calcium, sodium, and potassium.
• The outer core is about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel.
• The NiFe alloy of the outer core is very hot, between 4,500 ° and 5,500 ° Celsius (8,132 ° and 9,932 ° Fahrenheit).
• The metallic nickel – iron outer core is liquid because of the high temperature.
• The inner core is the innermost geologic layer of planet Earth, primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 20% of Earth's radius or 70% of the Moon's radius.
• The inner core is believed to be composed of an iron – nickel alloy with some other elements.
• The temperature at the inner core’s surface is estimated to be approximately 5,700 K (5,430 ° C; 9,800 ° F), which is about the temperature at the surface of the Sun.
• Earthquakes occur when movements along faults generate earthquakes.
• The epicenter of an earthquake is different from its focus.
• Normal Fault: The hanging wall slides down the foot wall.
• Reverse Fault: The hanging wall slides up the foot wall.
• Strike – slip Fault: There is no foot wall and hanging wall, the two tectonic plates slip side to side with each other.
• Since that Philippines is located along the Pacific Ring of Fire, geologists explain that there is a continuous source of heat deep under the earth, which melts rocks and other material causing it to tremble and vibrate on the surface of the earth.