A year in the life of Earth

In 2018, Earth picked up about 40,000 tons of interplanetary material, mostly dust, much of it from comets. Earth lost around 100,000 tons of hydrogen and helium,  light gases which escaped to outer space. Roughly 500,000 cubic kilometers of water fell on Earth’s surface as rain and snow—a tiny fraction of the 1.3 billion cubic kilometers of all oceans, but far more than the fresh water standing and flowing on Earth’s surface.

Bristlecone pines, which can live for millennia, each gained perhaps a hundredth of an inch in diameter, while the oldest Sequoias added a full inch of height.  Countless mayflies came and went. As of this writing, more than one hundred thirty-six million people were born in 2018, and more than fifty-seven million died.  That’s still more than two births for every death, but the exponential population expansion has finally begun to slow, and demographers predict it might level off at 11 billion before century’s end.

Tidal interactions are very slowly increasing the distance between Earth and the moon, which ended 2018 about an inch and a half further apart than they were at the beginning. The energy to pull moon from earth was taken from Earth’s rotation, so that each day is two ten-thousandths of a second longer than it was last year. Earth and the sun are also crept almost an inch further apart, but for different reasons, having to do mostly with changes in the sun’s gravitational pull as it converts some of its mass into energy radiated into space.

The Atlantic Ocean widened by about an inch as the rift valley along the Mid-Atlantic Ridge expanded. New material, in the form of magma rising to the seafloor, pushed apart the North American and Eurasian plates (North Atlantic) and the South American and African plates (South Atlantic). The East African Rift, at which one plate is splitting into two, also widened, but only by a quarter inch.  The end of 2018 finds the Himalayas half an inch higher than they were at the beginning of the year; they’re being pushed up as the Indian plate, moving about 3 inches this year, continues to plow into the Eurasian plate.

Some of Earth’s geological changes are visible well within a human lifetime. From May through September, the island of Hawaii gained more than a square mile of new coastal land in the form of lava from Kilauea. Anak Krakatau (Child of Krakatoa) in the Sunda Strait in Indonesia erupted explosively in 2018. It appeared in 1930 in the caldera left behind after the 1883 eruption of Krakatoa, and every year it grows by about 20 feet.

Read more from Mary Hrovat at 3QuarksDaily

Integrity is wholeness,
the greatest beauty is
Organic wholeness, the wholeness of life and things, the divine beauty
of the universe. Love that, not man
Apart from that, or else you will share man’s pitiful confusions,
or drown in despair when his days darken.
— Robinson Jeffers

 

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