Visualizing the Abundance of Elements in the Earth’s Crust

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Elements in the Earth’s crust provide all the basic building blocks for mankind.

But even though the crust is the source of everything we find, mine, refine, and build, it really is just scratching the surface of our planet.

After all, the innermost layer of the Earth, the core, represents 15% of the planet’s volume, whereas the mantle occupies 84%. Representing the remaining 1% is the crust, a thin layer that ranges in depth from approximately 5-70 km (~3-44 miles).

This infographic takes a look at what elements make up this 1%, based on data from WorldAtlas.

Earth’s Crust Elements

The crust is a rigid surface containing both the oceans and landmasses. Most elements are found in only trace amounts within the Earth’s crust, but several are abundant.

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%.

While gold, silver, copper and other base and precious metals are among the most sought after elements, together they make up less than 0.03% of the Earth’s crust by mass.

#1: Oxygen

Oxygen is by far the most abundant element in the Earth’s crust, making up 46% of mass—coming up just short of half of the total.

Oxygen is a highly reactive element that combines with other elements, forming oxides. Some examples of common oxides are minerals such as granite and quartz (oxides of silicon), rust (oxides of iron), and limestone (oxide of calcium and carbon).

#2: Silicon

More than 90% of the Earth’s crust is composed of silicate minerals, making silicon the second most abundant element in the Earth’s crust.

Silicon links up with oxygen to form the most common minerals on Earth. For example, in most places, sand primarily consists of silica (silicon dioxide) usually in the form of quartz. Silicon is an essential semiconductor, used in manufacturing electronics and computer chips.

#3: Aluminum

Aluminum is the third most common element in the Earth’s crust.

Because of its strong affinity for oxygen, aluminum is rarely found in its elemental state. Aluminum oxide (Al2O3), aluminum hydroxide (Al(OH)3) and potassium aluminum sulphate (KAl(SO4)2) are common aluminum compounds.

Aluminum and aluminum alloys have a variety of uses, from kitchen foil to rocket manufacturing.

#4: Iron

The fourth most common element in the Earth’s crust is iron, accounting for over 5% of the mass of the Earth’s crust.

Iron is obtained chiefly from the minerals hematite and magnetite. Of all the metals we mine, over 90% is iron, mainly to make steel, an alloy of carbon and iron. Iron is also an essential nutrient in the human body.

#5: Calcium

Calcium makes up about 4.2% of the planet’s crust by weight.

In its pure elemental state, calcium is a soft, silvery-white alkaline earth metal. It is never found in its isolated state in nature but exists instead in compounds. Calcium compounds can be found in a variety of minerals, including limestone (calcium carbonate), gypsum (calcium sulphate) and fluorite (calcium fluoride).

Calcium compounds are widely used in the food and pharmaceutical industries for supplementation. They are also used as bleaches in the paper industry, as components in cement and electrical insulators, and in manufacturing soaps.

Digging the Earth’s Crust

Despite Jules Verne’s novel, no one has ever journeyed to the center of Earth.

In fact, the deepest hole ever dug by humanity reaches approximately 12 km (7.5 miles) below the Earth’s surface, about one-third of the way to the Earth’s mantle. This incredible depth took about 20 years to reach.

Although mankind is constantly making new discoveries and reaching for the stars, there is still a lot to explore about the Earth we stand on.

How Has Car Safety Improved Over 60 Years?

Did you know that in 2019, there were 6.7 million car accidents in the U.S. alone?

This resulted in 36,096 deaths over the year—an awful statistic to say the least—but one that would be much worse if it weren’t for seatbelts, airbags, and other modern safety devices.

In this infographic, we’ve visualized data from the U.S. Bureau of Transportation to show how breakthroughs in car safety have drastically reduced the number of motor vehicle fatalities.

Measuring Safety Improvements

The data shows the number of fatalities for every 100 million miles driven. From a high of 5.1 in 1960 (the first year data is available), we can see that this metric has fallen by 78% to just 1.1.

What makes this even more impressive is the fact that there are more cars on the road today than in 1960. This can be measured by the total number of miles driven each year.

So, while the total number of miles driven has increased by 371%, the rate of fatalities has decreased by 78%. Below, we’ll take a closer look at some important car safety innovations.

1. The Seatbelt

The introduction of seatbelts was a major stepping stone for improving car safety, especially as vehicles became capable of higher speeds.

The first iteration of seatbelts were a 2-point design because they only looped across a person’s waist (and thus had 2 points of mounting). This design is flawed because it doesn’t hold our upper body in place during a collision.

Today’s seatbelts use a 3-point design which was developed in 1959 by Nils Bohlin, an engineer at Volvo. This design adds a shoulder belt that holds our torso in place during a collision. It took many years for Volvo to not only develop the device, but also to convince the public to use it. The U.S., for instance, did not mandate 3-point seatbelts until 1973.

2. The Airbag

The concept of an airbag is relatively simple—rather than smacking our face against the steering wheel, we cushion the blow with an inflatable pillow.

In practice, however, airbags need to be very precise because it takes just 50 milliseconds for our heads to collide with the wheel in a frontal crash. To inflate in such a short period of time, airbags rely on a chemical reaction using sodium azide.

The design of an airbag’s internal mechanism can also cause issues, as was discovered during the Takata airbag recall. As these airbags inflated, there was a chance for them to also send metal shards flying through the cabin at high speeds.

Dual front airbags (one for each side) were mandated by the U.S. government in 1998. Today, many cars offer side curtain airbags as an option, but these are not required by law.

3. The Backup Camera

Backup cameras became a legal requirement in May 2018, making them one of the newest pieces of standard safety equipment in the U.S. These cameras are designed to reduce the number of backover crashes involving objects, pedestrians, or other cars.

Measuring the safety benefits of backup cameras can be tricky, but a 2014 study did conclude that cameras were useful for preventing collisions. A common criticism of backup cameras is that they limit our field of vision, as opposed to simply turning our heads to face the rear.

Taking Car Safety to the Next Level

According to the National Highway Traffic Safety Administration (NHTSA), having both seatbelts and airbags can reduce the chance of death from a head-on collision by 61%. That’s a big reduction, but there’s still plenty of room left on the table for further improvements.

As a result, automakers have been equipping their cars with many technology-enabled safety measures. This includes pre-collision assist systems which use sensors and cameras to help prevent an accident. These systems can prevent you from drifting into another lane (by actually adjusting the steering wheel), or apply the brakes to mitigate an imminent frontal collision.

Whether these systems have any meaningful benefit remains to be seen. Referring to the table above shows that fatalities per 100 million miles have not fallen any further since 2010.