The isthmus of Panama formed due to convergent tectonics of the eastern Pacific subduction zone, which created a magmatic arc extending from southern North America.

[1] The combination of these forces produced the Isthmus of Panama and resulted in different sea surface salinity between the Pacific and Atlantic since 4.2 million years ago.

The Bocas del Toro Archipelago on the western Caribbean coast records local stratigraphy through this period, with Pliocene to Pleistocene coral reef carbonates overlying Miocene basalt and siliclastic shale.

[3] In the remote southeastern Darién Province, crystalline basement rock of the San Blas Complex forms massifs in the northeast and southwest, dating to the Cretaceous, Paleocene and Eocene.

These rocks and others in the north such as rhyolite, dacite, basaltic andesite, granodiorite and quartz diorite indicate that the region was a separate magmatic arc until 20 million years ago.

Complex faulting and folding formed the Chucunaque-Tuira Basin includes three kilometers of sediments from the Miocene deposited during the collision with South America.

The lofty Cordillera de Talamanca extends east from Costa Rica and contains Panama's highest peak, Volcán Barú, at 3,475 meters (11,401 ft).

Diurnal ranges are low; on a typical dry-season day in the capital city, the early morning minimum may be 24 °C (75.2 °F) and the afternoon maximum 29 °C (84.2 °F).

Temperatures are markedly cooler in the higher parts of the mountain ranges, and frosts occur in the Cordillera de Talamanca in western Panama, with pipes having been frozen at as low as 7,000 ft (2,100 m) elevation.

The cycle of rainfall is determined primarily by two factors: moisture from the Caribbean, which is transported by north and northeast winds prevailing during most of the year, and the continental divide, which acts as a rain shield for the Pacific lowlands.

This wind brings some precipitation to the Pacific lowlands, modified by the highlands of the Península de Azuero, which form a partial rainshield for much of central Panama.

Subsistence farming, widely practiced from the northeastern jungles to the southwestern grasslands, consists largely of corn, bean, and tuber plots.

The numerous islands of the Archipiélago de Bocas del Toro, near the Beaches of Costa Rica, provide an extensive natural roadstead and shield the banana port of Almirante.

Depths of 180 metres (591 ft) are reached only outside the perimeters of both the Gulf of Panama and the Golfo de Chiriquí, and wide mud flats extend up to 70 km (43 mi) seaward from the coastlines.

Geographic coordinates: 9°00′N 80°00′W / 9.000°N 80.000°W / 9.000; -80.000 Map references: Northern South America, the Caribbean and sometimes Central America Area: total: 75,420 km2 land: 74,340 km2 water: 1,080 km2 Land boundaries: total: 555 km border countries: Colombia 225 km, Costa Rica 330 km Coastline: 2,490 km Maritime claims: territorial sea: 12 nautical miles (22 kilometres) contiguous zone: 24 nautical miles (44 kilometres) exclusive economic zone: 335,646 km2 (129,594 sq mi) and 200 nautical miles (370 kilometres) or edge of continental margin Climate: tropical maritime; hot, humid, cloudy; prolonged rainy season (May to January), short dry season (January to May) Terrain: interior mostly steep, rugged mountains and dissected, upland plains; coastal areas largely plains and rolling hills Extreme points: Northernmost point: Point Manzanillo Southernmost point: Punta Mariato, Cerro Hoya National Park, Veraguas Westernmost point: Border with Costa Rica, Chiriquí Province Easternmost point: Border with Colombia, Darién ProvinceLowest point: Pacific Ocean 0 mHighest point: Volcan de Chiriqui 3,475 m Natural resources: copper, mahogany forests, shrimp, hydropower Land use: arable land: 7.16% permanent crops: 2.51% other: 90.33% (2011) Irrigated land: 346.2 km2 (2003) Total renewable water resources: 148 km3 (2011) Natural hazards: occasional severe storms and forest fires in the Darien area, earthquakes Environment - current issues: water pollution from agricultural runoff threatens fishery resources; deforestation of tropical rain forest; land degradation and soil erosion threatens siltation of Panama Canal; air pollution in urban areas; mining threatens natural resources Environment - international agreements: party to: Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Endangered Species, Environmental Modification, Hazardous Wastes, Law of the Sea, Marine Dumping, Ozone Layer Protection, Ship Pollution, Tropical Timber 83, Tropical Timber 94, Wetlands, Whaling signed, but not ratified: Marine Life Conservation Geography - note: strategic location at eastern end of Central America; controls Panama Canal that links Atlantic Ocean via Caribbean Sea with Pacific Ocean.