earth science

11 articles · All tags

• Urban Heat Islands: Why Cities Are Hotter Than Nearby Land
  An urban heat island is a city area that runs hotter than the countryside around it, mainly because dark surfaces absorb sunlight and buildings and roads store heat.
• What Is a River Delta and How Does It Form?
  A river delta is new land built where a river slows on entering a sea or lake, drops its sediment, and splits into channels that push the coastline outward.
• What Killed the Dinosaurs? The Chicxulub Impact
  The Chicxulub impact, about 66 million years ago off the Yucatán coast, triggered the mass extinction that ended the non-avian dinosaurs and most other species.
• How Are Caves and Karst Landscapes Formed?
  Caves and karst form when slightly acidic groundwater dissolves limestone along cracks, enlarging them over thousands of years into passages and sinkholes.
• Meandering Rivers and Oxbow Lakes: How They Form and Change
  A meandering river forms looping bends because its fastest flow erodes the outside of each curve, and an oxbow lake forms when a flood cuts through a loop neck.
• Ocean Currents
  Large-scale movements of seawater driven by wind, density differences, and Earth's rotation that redistribute heat around the planet.
• Earthquakes and Seismic Waves
  Sudden release of stress along faults generates seismic waves that travel through Earth, measured by seismographs and magnitude scales.
• Greenhouse Effect
  The warming of Earth's surface by greenhouse gases that absorb and re-emit infrared radiation, keeping the planet habitable.
• Water Cycle
  The continuous movement of water between atmosphere, land, and oceans through evaporation, condensation, precipitation, and runoff.
• The Rock Cycle
  The model describing how igneous, sedimentary, and metamorphic rocks form and transform over geological time.
• Fossilization
  The rare sequence of processes that preserves remains or traces of ancient organisms in the rock record.