Nicaragua

Nicaragua is one of Central America's most seismically active nations, experiencing frequent earthquakes from the Middle America [[subduction-zone]] off its Pacific coast as well as shallow crustal fault earthquakes within the densely populated Pacific lowland corridor. The Cocos Plate subducts beneath the Caribbean Plate along the Middle America Trench at approximately 7–8 centimetres per year, generating both large interplate megathrust events and deep intraslab earthquakes within the descending slab. The volcanic chain running the length of the Pacific zone — including active volcanoes Concepción, Momotombo, Cerro Negro, and Masaya — marks the arc above the [[subduction-zone]] and generates additional volcano-tectonic seismicity. Onshore, northwest-trending crustal faults running through the Pacific Depression (the lowland corridor containing Managua, León, and other major cities) have historically produced some of Nicaragua's most destructive earthquakes.

Nicaragua's capital Managua has been destroyed twice by earthquakes in the modern era. The 31 March 1931 earthquake (magnitude 5.6) destroyed most of the city and killed approximately 1,000 people, prompting rebuilding on the same vulnerable site. The 23 December 1972 Managua earthquake (magnitude 6.2) struck with the [[epicenter]] directly beneath the city, killing approximately 10,000 people, destroying 80 percent of Managua's commercial buildings, and leaving 250,000 homeless. The earthquake struck in the early morning hours and the subsequent fire — fed by broken gas lines — spread through the debris. The disaster redirected international aid into the hands of the Somoza regime, contributing to the social conditions that led to the 1979 revolution. The fault responsible (the Tiscapa Fault) passes directly through the city, and Managua has been rebuilt over the same active [[fault]] system. In 1992, a magnitude 7.6 offshore subduction earthquake generated a [[tsunami]] that struck the Pacific coast, killing 116 people and injuring hundreds more, one of the largest tsunami death tolls in Central America's modern era. The 2014 magnitude 6.0 earthquake near Tipitapa caused minor damage.

Nicaragua's tectonic situation places it in the most seismically coupled segment of the Middle America [[subduction-zone]]. The Cocos Plate subducting beneath Nicaragua is relatively young oceanic crust — formed at the East Pacific Rise only 15 to 25 million years ago — and its buoyancy and steeper subduction angle create a somewhat different seismic character than areas to the south. The volcanic arc erupts frequently, with Cerro Negro (now rebranded as La Cachimba) having had more than 25 eruptions since 1850. The Pacific Depression between the volcanic arc and the Pacific shoreline is a structural graben or half-graben formed by back-arc extension, and the faults bounding it represent significant seismic sources for the densely populated cities within. [[aftershock]] sequences from major Nicaraguan earthquakes tend to be energetic and can cause additional building collapses in already-damaged structures. Nicaragua's INETER institute maintains the national seismological monitoring network.