What Earth's Core Tells Us About Earthquake Resistant Buildings

On May 13, Google’s front page had a doodle of a sliced earth, with its shining molten core. It was the 127th birth anniversary of Inge Lehmann, the Danish seismologist who discovered that there was a solid inner core inside the soft, molten outer core of earth. She drew this inference when she noticed that certain seismic waves during an earthquake were detected by some seismometers in Europe. This would not have happened if earth’s core was entirely molten because such waves bent when traveling through liquid. Earthquakes taught Lehmann more about earth’s core. But, we know so little about the earth’s core. The survivors of Nepal earthquake are yet to recover from the destruction the tremor caused. It would be interesting to look into how the earth’s core is full of earthquake resistant materials that would protect us from such disasters if only we are willing to tap into them.

1. Homes made of lightweight steel, for instance, are more earthquake resistant. Steel is an alloys of iron and carbon. Carbon was known since antiquity, and is the fourth more abundant element in the universe. But long ago, iron was not even recognized as a resource. The metal was discovered only during the end of Stone Age, and iron is the most common element on earth.

2. If the roof of homes are as light as possible, they would be more earthquake resistant. Steel can me made lighter by adding aluminum. Aluminum is the most abundant metal in the earth’s crust, and was not recognized as a resource till well into the 19^th century.

3. Nickel-titanium alloy (nitinol) is expected to play a role in earthquake resistant buildings in the future. But, Nickel was discovered only in 1751, while attempting to extract copper from fake copper, another mineral. But, the earth’s inner core and outer are made of iron and nickel. Titanium was isolated only in 1825, though it lies within many mineral deposits like rutile and ilmenite that are common in the earth's crust. Rutile and ilmenite are found in almost all living things, including rocks, water bodies and soils.

The earth’s mass is entirely made of chemical elements, four thousand miles down. But, man’s mining operations are still measured in feet and not in miles. When we learn more about the earth’s core and when our mining operations go deeper into the earth, we would be able to find more minerals that make our homes earthquake resistant. This is not a remote possibility because humans can carry out mining operations thousands of feet deep into the earth more easily than he did ten feet long ago.