Makban

Makban
Name	Makban
Other name	Mount Makiling–Bulusan complex
Elevation m	1100
Location	Luzon, Philippines
Range	Laguna Volcanic Field
Coordinates	14°07′N 121°25′E
Type	Complex volcano / stratovolcanic field
Last eruption	1979 (phreatic)

Makban Makban is a volcanic complex in the Calabarzon region of Luzon, Philippines, known for geothermal activity and historic phreatic eruptions. The complex occupies a landscape between Laguna de Bay and Mount Banahaw and is integral to regional energy production and watershed systems. It has been the focus of scientific studies by Philippine and international institutions assessing hazards, geothermal resources, and biodiversity conservation.

Overview

Makban is situated within the Laguna Volcanic Field and is associated with the larger tectonic setting of the Philippine Mobile Belt, the Manila Trench, and the Philippine Fault System. The complex has been monitored by the Philippine Institute of Volcanology and Seismology (PHIVOLCS), which collaborates with the United States Geological Survey (USGS), the Japan Meteorological Agency (JMA), and academic centers such as the University of the Philippines and the Ateneo de Manila University. Regional authorities including the Department of Energy and the Department of Environment and Natural Resources engage in permitting, land management, and hazard mitigation. International partnerships have included geothermal developers from Ormat Technologies, Chevron, and Mitsubishi Heavy Industries in exploration and plant operation.

Geography and Geology

Makban occupies parts of the provinces of Laguna and Batangas and lies near municipalities such as Calauan, Los Baños, Alaminos, Santo Tomas, and Bay. The complex is geologically related to nearby features including Mount Makiling, Mount Banahaw, Taal Volcano, Mount Arayat, and the Sierra Madre range. Geophysical surveys reference structures like the Philippine Trench, the Verde Island Passage, and the South China Sea basin. Geological mapping has identified lithologies comparable to those at Mount Pinatubo, Mount Mayon, Mount Apo, and Mount Bulusan, and stratigraphic relations with Quaternary deposits mapped by the Philippine Institute of Volcanology and Seismology and the Commission on Volcanology. Key geomorphological features include fumarolic fields, solfataras, hot springs, and craters analogous to those at Kusatsu, Yellowstone, Rotorua, and Icelandic geothermal areas.

Volcanic History and Activity

The eruptive history includes phreatic events and hydrothermal unrest recorded in the 19th and 20th centuries, with monitoring records maintained by PHIVOLCS, the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), and networks such as Global Volcanism Program at the Smithsonian Institution. Seismic swarms, ground deformation measured by InSAR and GPS by groups from NASA and the European Space Agency (ESA), and geochemical analyses involving sulfur dioxide flux, helium isotopes, and gas ratios have been reported. Comparative studies reference eruption styles at Soufrière Hills, Mount Vesuvius, Mount St. Helens, and Ruapehu to contextualize hazards such as phreatic explosions, lahar generation similar to events at Nevado del Ruiz, and ashfall impacts as observed at Eyjafjallajökull. Risk assessments have involved the National Disaster Risk Reduction and Management Council, local disaster councils in Laguna and Batangas, and international agencies such as the Asian Development Bank for resilience planning.

Ecology and Biodiversity

The Makban area supports flora and fauna characteristic of Luzon montane and lowland ecosystems and shares species affinities with protected areas like Mount Banahaw–San Cristobal Protected Landscape, Mount Makiling Forest Reserve, and the Sierra Madre biodiversity corridor. Botanical inventories cite genera and families documented by the National Museum of the Philippines, the Botanical Society of the Philippines, and collaborations with Kew Gardens and the Field Museum. Faunal records include mammals, birds, amphibians, and reptiles studied by the Haribon Foundation, BirdLife International, Conservation International, and local universities. Habitat concerns mirror those in other Philippine hotspots such as Palawan, Mindoro, and the Cordilleras, with conservation efforts coordinated by the Protected Areas and Wildlife Bureau and NGOs like WWF-Philippines and the Philippine Eagle Foundation.

Human Use and Recreation

Makban hosts geothermal power facilities developed under concessions awarded and regulated by the Department of Energy and operated historically by companies including PNOC-EDC and private developers. Geothermal exploitation has involved drilling programs, production wells, steamfields, and binary/flash power plants, drawing technical expertise from Schlumberger, Halliburton, and Baker Hughes contractors during exploratory phases. Recreational use includes hiking, birdwatching, and visits to hot springs, with access managed by municipal tourism offices in Los Baños, Bay, and Santo Tomas and promoted by the Department of Tourism alongside tour operators and provincial tourism boards. Scientific and educational excursions are organized by institutions such as the University of the Philippines Los Baños, De La Salle University, and the International Union for Conservation of Nature (IUCN).

Cultural and Economic Significance

The complex contributes to regional electricity supply, rural livelihoods, and cultural landscapes linked to nearby sacred sites and pilgrimage destinations such as Mount Banahaw and the University of the Philippines Los Baños campus. Economic stakeholders include the National Grid Corporation of the Philippines, Electric Power Research Institute collaborations, local cooperatives, and agribusinesses relying on irrigation drawn from aquifers influenced by geothermal systems. Cultural heritage groups, municipal governments, and religious organizations have intersected with conservationists and developers over land use, echoing disputes and resolutions seen in resource governance cases like the Mt. Apo controversies, the Chico River watershed, and the Tubbataha management regime. International funders and multilateral agencies including the World Bank and Asian Development Bank have supported infrastructure and environmental assessment projects related to energy and watershed management in the region.

Category:Volcanoes of Luzon Category:Geothermal areas in the Philippines