We have already landed on the Moon, soon we might send humans to Mars, so it won’t come as a surprise if, in the future, we start planning for intergalactic travels. A question before you start thinking about the wonders lying outside our planet: Do we know every nook and corner of the Earth, or are there any mysteries left to be discovered/decoded? The answer is “no,” we don’t know everything about the Earth. Each day, scientists are discovering something new about this wonderful planet. Learning about Earth’s peculiarities would help us appreciate our planet even more. So, here are 10 weird things about the Earth that most people don’t know.
1. We don’t actually know who named the Earth.
Do you know Earth is the only planet not named after a Greek or Roman god or goddess? Also, no one knows who coined the word “Earth.” There are two root words for the name of our planet, and both are in different languages. Earth might have been derived from the English word “eor(th)e/ertha,” which means ground, or it might have been derived from the German word “erde,”‘ which also means ground.
According to the official gazetteer of planetary discovery, the name “Earth” comes from the Indo-European base “er.” This base produced the Germanic noun “ertho,” Danish and Swedish “jord,” the modern German “erde,” Dutch “aarde,” and English “earth.” (1, 2)
2. The Earth has another continent called “Zealandia.” The entire continent sank after breaking away from Australia around 65-80 million years ago.
From the Neoproterozoic (about 550 million years ago) until the Jurassic (about 180 million years ago), there existed the supercontinent Gondwana. The center of this supercontinent was Antarctica. The New Zealand continent, also known as ‘Zealandia” or Tasmantis,” was connected to Antarctica. Between 85 and 130 million years ago, Zealandia separated from Antarctica. After its separation from Australia about 60–85 million years ago, it started sinking. It is estimated that Zealandia submerged completely about 23 million years ago. Currently, 93% of Zealandia is submerged beneath the Pacific ocean.
Soon after researchers came to know about the existence of Zealandia, there was a debate that whether it should be considered as a continent, a microcontinent, or continental fragment. In 2017, a team of 32 scientists from 12 countries went on a nine-week voyage in the South Pacific to study Zealandia. They surveyed the landmass and drilled its seabed at six sites collecting 8,000 feet (2,500 meters) of sediment cores. The layers of sediment provided much insightful information about the geography and climate change over millions of years. Zealandia is officially still not considered as a continent even though many geologists from New Zealand, New Caledonia, and Australia believe that it fulfills all the requirements to be considered a continent. (1, 2, 3)
3. The Amazon Rainforest stays fertile due to phosphor that it gets from the Sahara Desert. The phosphor travels the Atlantic Ocean and a great part of the South American continent to keep the forest alive.
Can there ever exist any connection between the sand and scrub of the Sahara Desert and the dense humid jungle of Amazon Rainforest? Most of you will answer “no,” but guess what? There exists a huge connection, a relationship of such importance that one might not even exist without the other.
During the Holocene Period, northern Africa was lush green with vegetation. There were many lakes and rivers such as Lake Chad and the White Nile. This period was called the “African Humid Period.” The African Humid Period ended about 6,000 to 5,000 years ago. Vegetation declined, and lakes began drying up. The shells of dead diatoms, a major group of algae, now covered the vast expanse of the dried Lake Chad. Also, due to desertification, plants, trees, animals, and birds began to die. Slowly, the soil of Sahara became enriched with nutrients from the decomposing organisms.
At present, every year the wind blows away an average of 182 million tons of dust from the Bodélé Depression in Chad. The nutrient-rich dust crosses the Atlantic Ocean and falls over the Amazon basin. Every year, rainfall in the Amazon washes away many nutrients, including phosphorus, a key nutrient for plant growth. The dust from the Sahara Desert replenishes these lost nutrients and so helps to keep Amazon green. (1, 2, 3)
4. The Earth’s atmosphere actually goes past the Moon. The outermost layer, the geocorona, extends out to as much as 630,000 kilometers.
We have been taught in school that the atmosphere of the Earth ends in exosphere which extends out 700 km to 10,000 km. Now, scientists have found out that the last layer of Earth’s atmosphere extends much beyond that. The newly discovered last layer of the atmosphere has been named “geocorona.” It is a cloud of hydrogen atoms which becomes luminous in far-ultraviolet when sunlight falls on it. Scientists believe the geocorona extends to approximately 100,000 km (~15.5 Earth radii). Even our moon, which lies at a distance of 384,600 km, falls inside the geocorona.
The presence of the geocorona was known to scientists since the Apollo 16’s mission in 1972, but they didn’t know that it was so vast. The neutral hydrogen density of the geocorona lies in the order of one, or less than one, atom per cubic centimeter at the moon’s distance. There are just 70 hydrogen atoms per cubic centimeter (0.06 cubic inches) at an altitude of 37,000 miles (60,000 km) on the day side. (1, 2, 3)
5. There are mountains 660 km below our feet, i.e. on the transition zone, that had been revealed due to a massive earthquake that hit Bolivia in 1994.
Broadly, the Earth is divided into three layers: crust, mantle, and core. In reality, there are several other layers within the Earth that scientists have identified. One of them is the transition zone that lies within the mantle. Geophysicists from Princeton University in the US and the Chinese Academy of Sciences have discovered mountains lying about 660 km below the surface in the transition layer. The discovery has been made after studying a massive earthquake that hit Bolivia on 9 June 1994.
The 8.2 Bolivian earthquake had the focal point at a depth of just under 650 km. Its tremor was the first one to be measured on a modern, seismic network. These 1994 seismic recordings were studied by geophysicists recently. They studied the waves as it transitioned between layers and traveled up to 660 km. At this depth, the researchers found a division between the lower part of the mantle and its upper zone. Based on their study, the researchers concluded that there exists a zig-zagging mountain range at the meeting point of the mantle’s upper and lower parts. (1, 2, 3)