Guatemala's geography: a capital moved by volcanoes and faults

Why the capital of Guatemala kept moving

Pedro de Alvarado declared the Kaqchikel capital of Iximche the first capital of Guatemala on 27 July 1524 and named it Santiago de los Caballeros de Guatemala. The Spanish took the name from their Nahuatl-speaking allies, for whom the place was Quauhtemallan, "forested land", and the name spread from the town to the whole kingdom. The settlement lasted three years. Continuous Kaqchikel attacks drove the Spanish out of nearby Tecpán in 1527, and they refounded the capital in the Almolonga Valley to the east, on the site of what is now the San Miguel Escobar district of Ciudad Vieja.

That second site was the first to be taken by the ground. In 1541 earthquakes and an avalanche buried it entirely, in the wording of the UNESCO listing; the Wikipedia account of the country calls the same event a volcanic mudflow. The third capital was laid out in the Valley of Panchoy, or Pacán, and inaugurated in March 1543, at 1,530 metres. It held the seat of the Captaincy-General for 230 years and came through floods, eruptions and repeated tremors before the Santa Marta earthquakes of 1773 destroyed much of it.

The crown then ordered the capital moved to a safer site, and Guatemala City was founded there in 1776. Some residents stayed behind in the ruined town, which came to be called La Antigua Guatemala, and it lay mostly abandoned for almost a century, to the middle of the 1800s, when coffee and grain brought money back into the valley. Its surviving churches carry the mark of the ground they stand on. The regional style the UNESCO listing calls Barroco antigueño builds massive walls and low bell towers designed to withstand the frequent earthquakes.

The move of 1776 changed the site and kept the geology. Guatemala City sits at about 1,500 metres in the same volcanic highland, and it was largely rebuilt after the earthquakes of 1917 and 1918. Antigua still sits beneath three volcanoes, Agua, Fuego and Acatenango, and Britannica records that lava from Pacaya is sometimes visible from the capital. Every Spanish capital the country has had stood in the band of the country where the ground moves most, because that band also carried the productive soil and most of the people.

How Guatemala divides into separate grounds

Britannica describes the surface as four major features, and they run in belts from the Pacific northward. The first is the Pacific coastal plain, 40 to 50 km wide and about 240 km long from east to west, sloping from roughly 450 metres at the foot of the volcanoes down to sea level. It is built of volcanic debris, and Britannica describes its soils as productive.

Behind it stands the volcanic row: a line of cones of geologically recent origin, about 300 km long between the Mexican and Salvadoran borders. North of the cones lies an older volcanic tableland, deeply eroded and dissected, averaging 2,750 metres near Mexico and falling to about 900 metres at the border with El Salvador. Ash-filled basins and lakes are scattered across it, and Lake Atitlán fills an endorheic volcanic basin there, with no outlet to the sea.

The third belt is the sierras, which arc eastward from Mexico for about 340 km and carry on into northern Honduras. The Sierra de los Cuchumatanes in the west rises above 3,000 metres. Eastward the lower ranges of Chamá, Santa Cruz, Chuacús, Las Minas and the Montañas del Mico are separated by deep valleys that open onto a narrow Caribbean shore. The sierras form the barrier between the crowded volcanic south and the north.

The north is the Petén, a large, low, rectangular block that juts northward into the Yucatán Peninsula. It is a limestone platform shared with Mexico and Belize, mostly below 300 metres, and its surface is knobbly and hilly with scattered lakes, Lake Petén Itzá among them. Much of the Petén drains by subsurface flow through the rock.

The four belts carry very different shares of the people. Britannica puts about three-fifths of the population in the volcanic uplands and the Pacific plain south and west of Guatemala City, and the 2018 census counted 545,600 people in the department of Petén, 3.7% of the 14,901,286 enumerated nationally that year.

Which volcanoes Guatemala counts as active

The sources do not agree on how many volcanoes the country has. Britannica describes a string of 27 across the south; the two Wikipedia articles on the country both give 37. They also disagree on which are active. The geography article names three, Pacaya, Santiaguito and Fuego, and the country article adds Tacaná on the Mexican border as a fourth. Britannica calls the same first three "continuously active".

The heights vary by source as well. Tajumulco in the western department of San Marcos is the highest point in the country at 4,220 metres in Britannica and in both Wikipedia articles. Fuego is 3,835 metres in one passage of Britannica and 3,763 metres in another, and the Smithsonian's Global Volcanism Program lists it at 3,799 metres.

Santiaguito differs from the others in kind. Britannica calls it the growing summit on the southern flanks of Santa María, and it has its own observatory, one of the stations run by INSIVUMEH, the national institute for seismology, volcanology, meteorology and hydrology.

Fuego has been erupting since January 2002, and the Global Volcanism Program has recorded eruptions there back to 1531. Its worst event in recent history began on 3 June 2018. Pyroclastic flows ran down the ravines on several flanks and buried San Miguel Los Lotes and El Rodeo, about 10 km south-east of the summit at the foot of the Las Lajas ravine; 110 deaths were reported and at least 197 people were missing and presumed dead. Rain from 6 June produced more than 30 lahars through the rest of that month. In the week of 23 to 30 September 2026, INSIVUMEH was still reporting one to seven explosions an hour at Fuego, with ash falling on Panimaché II and Yepocapa, each about 8 km from the summit.

What happens along the Motagua fault

Two plate boundaries meet under the country. Off the Pacific coast lies the Middle America Trench, where the Cocos Plate sinks beneath the Caribbean Plate, and that subduction feeds the volcanoes inland. The highlands sit on the Motagua Fault, part of the boundary between the Caribbean and North American plates, which has produced several major earthquakes in historic times.

Britannica describes the same line from the surface. The Motagua flows east and the Cuilco west through a single structural trough, and that trough marks the boundary between the volcanic south and the sierras of the middle of the country.

On 4 February 1976 the fault produced a magnitude 7.5 earthquake. The Wikipedia article on the country gives the death toll as more than 25,000; its geography article gives more than 23,000, in the Central Highlands. On 7 November 2012 a 7.4 earthquake centred off the Pacific coast killed dozens and was felt as far away as Mexico City.

Britannica's summary of the volcanic region links the two problems: three-fourths of the population and most of the major cities lie in the volcanic region and on the Pacific slope, and the eruptions and earthquakes of that zone "have repeatedly taken a heavy toll of property and life".

Where the rivers of Guatemala drain

The country drains to three seas. Rivers on the Pacific side are short and shallow, falling straight off the volcanic row across the narrow plain. The rivers of the other two slopes are longer and deeper.

The Caribbean slope is fed by the Motagua, about 400 km long, which drains the highlands eastward and is navigable in its lower reach, where it forms the boundary with Honduras. The Polochic and the Río Dulce both belong to the basin of Lake Izabal, 589.6 km² of water close to the Caribbean coast. The Sarstún forms the boundary with Belize. Along the Cahabón, at Semuc Champey, the river has travertine karst formations.

The Gulf of Mexico slope belongs to the Usumacinta, which forms the boundary between Petén and the Mexican state of Chiapas, and to its tributaries La Pasión and San Pedro. Most of the sierra region drains north into it.

In the Petén the drainage goes underground. CONAP, the national council for protected areas, writes that karst conditions set the hydrology of the Maya Biosphere Reserve, which forms the headwaters of three international basins, the San Pedro chief among them on the Gulf side and the Río Azul on the Caribbean side. The water level in many of its lagoons rises and falls by up to two metres between seasons, and Britannica notes extensive flooding in the rainy season. The Wikipedia country article lists 252 wetlands nationally, made up of five lakes, 61 lagoons, 100 rivers and four swamps.

The geographic data in the Wikipedia geography article note that the Pacific coast has no natural harbours, and the ports reflect that. Puerto de San José serves the Pacific side, and Santo Tomás de Castilla on the Caribbean is the headquarters of the navy.

How altitude sets the temperature in Guatemala

The climate is arranged by height more than by latitude. Britannica's bands put average monthly temperatures at 21 to 27 °C below 900 metres, 16 to 21 °C between 900 and 1,500 metres, and 10 to 16 °C between 1,500 and 2,700 metres. Above about 2,700 metres temperatures are marginal for crops, though animals can be grazed. Guatemala City at 1,500 metres and Quetzaltenango at 2,350 metres sit in the two middle bands.

INSIVUMEH's report on the climate of 2023 shows the spread in single readings. The highest temperature recorded that year was 41.8 °C at La Fragua in Estanzuela, Zacapa, on 28 April, in the dry middle Motagua valley, and Flores in the Petén reached 41.6 °C on 11 and 16 June. The lowest was −5.6 °C at Labor Ovalle in Olintepeque, Quetzaltenango, on 19 December 2023, and all five of the lowest readings INSIVUMEH lists for the year were taken in that department. The station with the lowest annual mean in 2023 was San Marcos, at 14.22 °C. On the Pacific side, Champerico averaged 29.89 °C.

Rainfall follows exposure to the wind. Britannica gives more than 3,800 mm a year on the higher Pacific-facing slopes of the volcanic row and on the north- and east-facing sides of the sierras, while the middle Motagua valley has near-desert conditions. The south and east receive 1,000 to 2,000 mm, and the areas closest to the Caribbean about twice that. A dry season generally runs from November to April, though trade winds off the Caribbean bring rain all year to the slopes that face them. INSIVUMEH measured 1,944 mm nationally in 2023, 170 mm below the 1991 to 2020 average, and its series from 1981 to 2023 runs between 1,714.4 mm in 2009 and more than 2,500 mm in 2010.

The national mean temperature in 2023 was 25.11 °C, 1.14 °C above the 1991 to 2020 average, and the series from 1981 to 2023 shows warming of 0.19 °C a decade. The 2023 season also brought 22 cold fronts, against an average of 16.

The storms come mainly in September and October, and the damage is done by water. Hurricane Mitch in October 1998 displaced nearly 100,000 people in Guatemala. Hurricane Stan in October 2005 killed more than 1,500, through flooding and landslides, and Hurricane Eta in November 2020 left more than 100 people dead or missing.

What is left of the forested land

The vegetation follows the belts. Britannica records dense rainforest broken by patches of savanna in the Petén, and oak and pine in the sierras. In the volcanic highlands the pine, fir and oak have been largely cleared except on the highest slopes, and on the Pacific plain the original forest and savanna have mostly gone. The overwhelming majority of the timber cut is burned as fuel. A reserve for the quetzal, the national bird, has been set aside in the sierras near Cobán.

Guatemala's national forest-monitoring group has measured the loss department by department. Between 1991/93 and 2001 the country lost an average of 73,148 hectares of forest a year, a rate of 1.43% annually. The Petén held 2,624,643 hectares of forest at the start of that period, just over half of the national 5,121,629, and it accounted for 331,034 of the 563,176 hectares of net loss. Global Forest Watch, working from satellite imagery, counts 1,890,560 hectares of tree cover lost from 2001 to 2024, about 24.6% of the cover present in 2000.

Most of what remains in the north lies inside the Maya Biosphere Reserve, created by Decree 5-90 of the Congress of the Republic. CONAP gives its extent as 2,090,667 hectares, in a page published in February 2024; the Wikipedia country article gives 2,112,940. CONAP counts 2,800 vascular plant species in the reserve, 34% of the national total, along with 513 bird species, 71% of those recorded in the country, and 122 mammal species, 64% of the country's mammals.

Tikal National Park sits inside it at 57,600 hectares of wetland, savanna, broadleaf and palm forest. It is inscribed by UNESCO on both natural and cultural criteria, and its record lists five cat species, the jaguar and the puma among them, and more than 300 species of birds. In 1995 Decree 64-95 added four protected complexes in southern Petén, covering about 411,379 hectares.

Where Guatemalans live on this ground

Britannica's figures place about three-fifths of the population in the volcanic uplands and the adjacent Pacific plain south and west of the capital, a little more than a tenth to the east and south, the rest in the sierras and the fewest in the Petén. About half the population is urban, and nearly half of that urban half lives in metropolitan Guatemala City. The 2018 census counted 3,015,081 people in the department of Guatemala, 20.2% of the national total.

The settlement map follows the line where the volcanoes meet the plain. Retalhuleu, Mazatenango and Escuintla stand along the junction of the upper coastal plain and the volcanic row. In the sierras the main centres are Zacapa in the east, Cobán in the north and Huehuetenango in the west. In the highlands, maize, beans and squash are grown for the household on small farms or milpas, while coffee, cotton, sugarcane, bananas and cattle for export are raised on the large estates of the Pacific piedmont, the coastal plain and the lower Motagua valley.

The Petén is the part of the country that is filling. Its population was 224,884 in 1994 and 545,600 in 2018, and between the 2002 and 2018 censuses it grew 2.5% a year against 1.8% nationally. The 2018 census classed 21.2% of the population of Petén as migrants into the department. Britannica records that many people displaced during the civil war moved into its sparsely populated land.

The land borders total 1,667 km and the coastline about 400 km, shared between the Pacific and a short stretch on the Gulf of Honduras. The border with Belize carries a dispute. Guatemala has long claimed all or part of Belizean territory and recognised Belize's independence on 6 September 1991, and the Wikipedia country article records the dispute as unresolved and under negotiation through the Organization of American States. This catalogue records that the claim exists and takes no position on it.