Reference Terms
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Sea level
Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface. Defining the reference level, however, involves complex measurement, and accurately determining MSL can prove difficult. Sea level has changed over geologic time. During the most recent ice age (at its maximum about 20,000 years ago) the world's sea level was about 130 m lower than today, due to the large amount of sea water that had evaporated and been deposited as snow and ice in northern hemisphere glaciers.
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Earth & Climate News
July 19, 2026
July 19, 2026 The asteroid that wiped out the dinosaurs was likely an exceptionally rare CO chondrite from a distant region of the solar system. Its unusual chemistry suggests that planet-cooling dust and debris, ...
July 18, 2026 Scientists have found evidence that a major Cascadia earthquake could trigger a second quake on the San Andreas Fault. The discovery came from unusual sediment layers formed by underwater landslides ...
July 18, 2026 A catastrophic asteroid breakup may have triggered a huge wave of impacts across the inner solar system about 800 million years ago. The debris was launched from near a gravitational gateway controlled by Jupiter, sending fragments toward Earth, the ...
July 18, 2026 Seismic waves have revealed that the oceanic plate beneath the Ontong Java Plateau was dramatically transformed by the colossal volcanic activity that created it more than 100 million years ago. Researchers found a complex structure of horizontal ...
July 17, 2026 Tiny plastic particles in drinking water may be doing more than contaminating the environment. New research suggests nanoplastics can actually help harmful bacteria survive by strengthening the slimy biofilms they form inside water systems. These ...
July 17, 2026 A major DNA study has rewritten the koala's evolutionary story, revealing that the species suffered a dramatic population collapse about 100,000 years ago, long before humans arrived in Australia. By calculating the koala's mutation rate for the ...
July 16, 2026 Researchers have created self-destructing living plastic that uses engineered bacteria to completely break itself down when activated. The material degrades in just six days without creating ...
July 16, 2026 Scientists have identified a hidden feedback loop that may explain how Earth has regulated its climate for tens of millions of years. As sea levels rose and fell, they changed how much phosphate reached the open ocean, affecting marine life and the ...
July 15, 2026 NASA's PACE satellite captured the Black Sea glowing turquoise during its annual phytoplankton bloom. The vivid color comes from massive numbers of coccolithophores, microscopic organisms whose reflective shells brighten the water enough to be seen ...
July 14, 2026 The world's longest-running soil warming experiment has revealed an unexpected climate concern. After nearly four decades, researchers found that warming can cause microbes to break down stable soil carbon that scientists once believed was largely ...
July 12, 2026 Scientists discovered that extreme deep-sea pressure squeezes valuable nutrients out of sinking organic particles, providing an unexpected food source for ocean microbes. The finding could rewrite our understanding of both deep-ocean ecosystems and ...
July 12, 2026 Why do beaches today have seashells from clams and snails instead of brachiopods? A new study suggests the answer lies in Earth's greatest mass extinction, when warming oceans and falling oxygen levels wiped out animals that couldn't adapt. Species ...
Latest Headlines
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July 11, 2026 Two striking Asian praying mantis species that have rapidly spread across Europe have now been officially classified as invasive, raising new concerns about their impact on native wildlife. Boosted ...
July 10, 2026 A newly discovered underwater volcanic eruption north of Papua New Guinea is unfolding in one of the world's most poorly mapped ocean basins. Satellites have spotted steam plumes, ash, thermal ...
July 10, 2026 A next-generation pesticide designed to kill crop pests may also be interfering with the reproductive health of bumblebees. Researchers discovered that low-dose exposure to sulfoxaflor changed gene ...
July 10, 2026 Mount Etna has long puzzled geologists because it doesn't fit any of the three classic ways volcanoes are thought to form. A new study suggests it may instead be fueled by ancient pockets of magma ...
July 9, 2026 Oak trees keep absorbing carbon dioxide long after their annual growth has ended, revealing that photosynthesis and wood production are not as closely linked as scientists once believed. The finding ...
July 8, 2026 Ocean temperature patterns appear to act as a natural brake on the global spread of drought, preventing vast areas of the planet from drying out simultaneously. Researchers found that shifting ...
July 5, 2026 Scientists have uncovered a hidden weakness beneath the Pacific Ocean that helps explain why Japan’s catastrophic 2011 earthquake and tsunami ...
July 3, 2026 Scientists have uncovered new evidence that fireworks can pollute both the air and water in ways that extend beyond the visible smoke. The findings show that leftover debris, fine particles, and ...
July 3, 2026 A new study found that not all geoengineering ideas are created equal. Brightening marine clouds over the eastern Pacific could dramatically weaken ...
July 2, 2026 A pioneering climate scientist is challenging a U.S. government report that cited his research while reaching what he says is the exact opposite ...