News about Earth: 7 News Sites That Work to Educate and Inspire You

On Earth Day (and every other day), it's essential to stay informed on the state of our planet. Here are seven news sites designed to ignite and motivate your inner environmental scientist.

National Geographic has long been a pioneer in environmental science journalism, always featuring professional photos to captivate readers of all ages. Explore its stories to discover how space explorations and Earth data benefit society.

Earth’s Fifth Layer

Recently, scientists have been uncovering the mysteries of Earth's internal structure. This includes understanding how its core works and where our oceans originate from.

Scientists once thought our planet consisted of four layers, such as the crust, mantle, outer core and inner core.

Researchers have recently uncovered that Earth has an additional layer, detected through seismic waves generated by earthquakes. This fifth layer could fundamentally change how we view Earth's interior.

The crust, also referred to as the lithosphere, is the thinnest layer on our planet. It varies in thickness from 5-10km beneath oceanic crust up to 50-80 km beneath continental crust and composed primarily of different kinds of rocks.

Most of Earth's surface is covered by crust, made up of rocks formed over 4.4 billion years ago. This includes minerals like aluminosilicates, silica, granite, iron and other rock types.

Two primary types of crust exist: oceanic (which primarily consists of basalt), and continental (made up of rock materials like granite, marble and silicate). Both crust types are layered from Earth's surface towards its centre.

The mantle, on the other hand, is that region between our planet's crust and core. It consists of solid rocks that were once molten. Though not liquid, this region can flow over long time scales.

That is why the mantle appears to 'flow' in places on our planet such as volcanoes, earthquakes and mountains. Furthermore, the mantle contains a great deal of igneous rock.

Our planet experienced intense pressure that caused elements in its mantle to be forced down towards the core and liquefied.

Earth’s Inner Core

The Earth's core is a solid ball of iron, nickel and molten rock that measures 1500 miles thick and extremely hot. Estimates place it between 7200-9000 degrees Fahrenheit (4000-4000 degrees Celsius).

Seismologists have been studying the core for decades, as it provides insight into Earth's rotation and magnetic field. But their complex behavior remains a mystery to this day.

Research suggests the core was formed relatively recently, within the past billion years or so. They note evidence of heat conduction at least twice as fast as it cools and its size only slightly larger than the crust's. This implies it took less than a billion years for the inner core to form and likely much less time for it to reach its current size.

Scientists have been able to map the shape and size of Earth's core by measuring waves reflected off it. These P-waves, or pulse waves as they're commonly known, bounce off at various points on opposite sides of planet and can be measured by seismic stations on either side.

Powerful earthquakes send seismic waves quickly through the core. But once they hit the crust, they slow down and become increasingly unpredictable.

As these waves propagate, scientists can analyze them to determine whether the core is spinning and where. By comparing time lags and perturbations between these waves, scientists can calculate how fast or slowly the core is rotating.

Recently, a study suggests the core is spinning faster east to west than it did in the 1970s. The researchers suggest this shift is caused by an internal conflict between electromagnetic and gravitational forces within the core.

Superrotation, or tug-of-war between the planet's core and outer atmosphere, is thought to be a driving force in its spinning. As such, its size and shape may change over time as its magnetic field expands or contracts depending on where it hits. This shift is essential for our planet's safety as a result of such variations.

Earth’s Magnetic Field

The Earth's magnetic field is one of the most significant aspects of our planet. You may be familiar with its effects on navigation if you have ever used a compass while sailing or walking along a mountaintop, but did you also know that it has an immense effect on life itself?

Our Earth is constantly enveloped by a magnetic field, which changes depending on the time and location. This field is generated by the molten metal outer core of our planet which continuously swirls in whirlpools caused by Earth's rotation. These currents create electrical currents throughout its molten core which then generate the magnetic field around us.

Although our magnetic field does not shield us from photons - the most abundant type of radiation on Earth (i.e., light), it does protect us from energetic particles like solar wind and cosmic rays that can harm DNA and other molecules, leading to diseases like cancer.

But there have been times in Earth's history when the magnetic field has drastically shifted. These events, known as geomagnetic reversals, include the Brunhes-Matuyama reversal which occurred approximately 780,000 years ago and caused significant change to our planet's magnetic field.

Jacob Svensmark, a postdoctoral researcher at Oxford University, has been researching the potential effects of this change on atmospheric ionisation rates worldwide. To model these effects, he used computer models to estimate global ionisation rates as the field was altered.

He observed the greatest increase in ionisation at the equator, where it rose by 25%. By comparison, ionization was almost zero at polar regions.

Scientists are striving to understand what might cause these reversals and how to predict them in the future. This work is especially vital since changes in geomagnetic field strength can provide scientists with clues as to how deep Earth processes might shift over hundreds of millions of years.

Earth’s Oceans

The oceans are essential components of Earth's ecosystem and cover the largest surface area of water on the planet. Not only do they play a major role in controlling water flow, but also play an important role in climate change mitigation efforts.

The majority of life on Earth depends on the sea for survival. From microscopic algae to blue whales - everything relies on this vital resource for food and shelter.

One of the most fascinating facts about the ocean is its constant evolution. With 3 billion years under its belt, it has undergone drastic changes and continues to shape our world even today.

This is because the ocean is moving in two directions - horizontally and vertically. This movement is caused by gravity, wind (the Coriolis Effect), and water density.

Oceans possess a system of circulating currents that are driven by salinity and temperature. These currents move ocean water in both directions: towards the sun and toward tides.

These currents are vital in the transfer of heat, the movement of species and coral reef formation. Furthermore, they regulate carbon cycles and weather patterns.

Researchers have recently discovered that some organisms living deep in the ocean possess enzymes called piezolytes, which enable them to survive under extreme pressure. These enzymes reside within their cell membranes and proteins in what's known as "the hadal zone," or deep sea bottom.

This discovery could provide new insight into both the origin of and formation of the oceans. Some geologists speculate that water from comets landed on Earth, slowly seeping out from beneath the mantle; however, this new finding lends credence to the notion that oceans originated deep inside Earth itself.

The oceans of Earth are a vast web of life, landforms and habitats that has been evolving ever since the planet formed. From the deepest trench to mid-ocean ridge, they have become an integral component of Earth's ecosystem.