A natural phenomenon is an observable event which is not man-made. Examples include: sunrise, weather, fog, thunder, tornadoes; biological processes, decomposition, germination; physical processes, wave propagation, erosion; tidal flow, and natural disasters such as electromagnetic pulses, volcanic eruptions, and earthquakes. Physical phenomena The act of: Freezing Boiling Gravity Magnetism Gallery Chemical phenomena Oxidation Fire Rusting Biological phenomena Metabolism Catabolism Anabolism Decomposition – by which organic substances are broken down into a much simpler form of matter Fermentation – converts sugar to acids, gases and/or alcohol. Growth Birth Death Population decrease Gallery Astronomical phenomena Supernova Gamma ray bursts Quasars Blazars Pulsars Cosmic microwave background radiation. Geological phenomena Mineralogic phenomena Lithologic phenomena Rock types Igneous rock Igneous formation processes Sedimentary rock Sedimentary formation processes (sedimentation) Quicksand Metamorphic rock Endogenic phenomena Plate tectonics Continental drift Earthquake Oceanic trench Phenomena associated with igneous activity Geysers and hot springs Bradyseism Volcanic eruption Earth's magnetic field Exogenic phenomena Slope phenomena Slump Landslide Weathering phenomena Erosion Glacial and peri-glacial phenomena Glaciation Moraines Hanging valleys Atmospheric phenomena Impact phenomena Impact crater Coupled endogenic-exogenic phenomena Orogeny Drainage development Stream capture Gallery Meteorological phenomena Violent meteorological phenomena are called storms. Regular, cyclical phenomena include seasons and atmospheric circulation. climate change is often semi-regular. Atmospheric optical phenomena Oceanographic Oceanographic phenomena include tsunamis, ocean currents and breaking waves. gallery See also Act of God Electrical phenomena Materialism Midnight Sun Black Holes Natural Environment Nature Transient lunar phenomenon References Atmospheric optical phenomena Earth phenomena Geography terminology Nature-related lists