Earth science

Outwash plain

Outwash plain (glacial outwash)

Ozone layer

Ozone layer: structure, chemistry, history, and global importance

Pacific hurricane

Pacific plate

Pacific Ring of Fire

Palaeocene

Palaeoclimatology

Palaeoclimatology: study of Earth's past climates

Palaeogene

Palaeoproterozoic

Palaeoproterozoic Era

Palaeozoic

Palaeozoic Era

Paleontology

Paleontology: the science of fossils, past life and Earth's history

Pangaea

Pannotia

Pannotia: the late Neoproterozoic supercontinent

Parent peak

Parent peak (topography)

Parinacota Volcano

Particularly Dangerous Situation

Particularly Dangerous Situation (PDS): meaning, use, and significance

Pedogenesis

Pedogenesis: Processes, Factors and Importance of Soil Formation

Pennsylvanian

Pennsylvanian: the Upper Carboniferous epoch in North America

Peridot

Peridot: the gem-quality form of olivine and its properties, history, and uses

Peridotite

Peridotite: an ultramafic igneous rock of the Earth's mantle

Period (geology)

Permafrost

Permafrost: frozen ground, processes, distribution, and consequences

Permian

Permian Period: Last Chapter of the Paleozoic and the Great Extinction

Permian–Triassic extinction event

Permineralization

Permineralization: how mineral-rich fluids preserve biological structure

Petrified wood

Petrified Wood: Fossilized Trees and the Process of Petrification

Petroleum

Petroleum industry

Petrology

Petrology: The Scientific Study of Rocks

Phanerozoic

Phanerozoic Eon: the Age of Visible Life

Pitchblende

Planetary core

Planetary geology

Plate boundary

Plate tectonics

Pleistocene

Pleistocene: Ice Ages, megafauna, and the rise of modern humans

Plinian eruption

Pliocene

Plutonism

Plutonism — the theory that igneous rocks form from Earth's internal heat

Polar climate

Polar climate: definition, characteristics, distribution and impacts

Polar low

Polar low — mesoscale cyclones of the polar oceans

Polar night

Polar night: prolonged winter darkness in Earth's polar regions

Polar vortex

Popocatépetl

Popocatépetl: Mexico’s active stratovolcano

Port Silt Loam

Portland limestone

Precambrian

Precambrian: Earth's early supereon from formation to the rise of complex life

Precipitation

Precipitation: forms, formation, measurement, and impacts