Extrusive Volcanic Landforms: Geysers and Hot Springs
Geography › Geomorphic Processes and Landform Evolution · Topic 3.7
Extrusive volcanic landforms are formed by materials that reach the surface: lava flows, cones, craters, calderas, lava domes and plateaus, and also the features of hot water, namely geysers, hot springs and fumaroles. A geyser is a hot spring that erupts a jet of hot water and steam at intervals, because groundwater heated by hot rock near the surface is trapped and boils under pressure. A hot spring flows continuously, with water above body temperature. These features occur in volcanic and geothermal regions.
6 min read · UPSC Prelims · Geography · Geomorphic Processes and Landform Evolution
At a Glance
- Geyser Periodic jet of hot water and steam
- Hot spring Continuous flow of warm water
- Fumarole Vent of steam and gases
- Famous geyser Old Faithful, Yellowstone (USA)
- Indian examples Manikaran, Tattapani, Rajgir, Bakreshwar
- Exam link UPSC Prelims, Geography: Geomorphic Processes and Landform Evolution
Where Does It Fit?
This topic follows the one on intrusive landforms and covers the surface features formed by volcanic heat. It completes the study of volcanic landforms before the topics on the activity status and the distribution of volcanoes. Previous topic: Intrusive Volcanic Landforms: Batholiths, Laccoliths, Lapoliths, Phacoliths, Sills, Dykes. Next topic: Extinct, Dormant and Active Volcanoes.
What Are the Extrusive Volcanic Landforms?
In short: extrusive landforms are built at the surface by lava, ash and hot water.
- Cones and craters: a crater is the bowl-shaped opening at the top of a volcano, and the cone is built by lava and ash around it. The main kinds are in Volcanoes: Types (Shield, Composite, Caldera, Flood Basalt, Mid-Ocean Ridge).
- Lava domes: mounds of thick, sticky lava piled over a vent.
- Lava plateaus and plains: huge sheets of basalt from fissures, like the Deccan Traps.
- Volcanic necks and plugs: the hardened lava in the vent, left standing when the cone is eroded.
- Fumaroles, mud pots, geysers and hot springs: features of gas and hot water in volcanic regions.
What Are Geysers?
A geyser is a hot spring that erupts periodically, shooting a column of hot water and steam into the air. Geysers need three things: a source of heat, plenty of water, and a plumbing system of narrow channels with constrictions that trap the water. Water at depth is heated above the normal boiling point because of the pressure; when it rises and the pressure falls, it flashes to steam and expels the water above it. The process repeats as the system refills. Geysers are rare and occur in only a few places: Yellowstone in the United States, which has over half of the world’s geysers, including Old Faithful, which erupts about every 90 minutes or so; Iceland, where the word geyser comes from the Geysir; Kamchatka in Russia; El Tatio in Chile; and New Zealand. Many geysers are in volcanic regions, along plate boundaries or over hotspots.
What Are Hot Springs and Where Are They Found in India?
A hot spring is a spring where groundwater, heated by contact with hot rock or magma, flows out at the surface at a temperature above the surroundings, without erupting. Fumaroles are vents that release gas and steam, and mud pots form where acidic gases dissolve rock to clay. India has several hundred thermal springs grouped by the Geological Survey of India into geothermal provinces, mostly along the Himalayas, along the Narmada-Son-Tapi rift valleys, in the west coast and in the Godavari valley.
| Region | Examples |
|---|---|
| Himalayas | Manikaran (Himachal Pradesh), Tapovan and Yamunotri (Uttarakhand), Puga and Chumathang (Ladakh), Yumthang (Sikkim) |
| Rift valleys of central India | Tatapani (Chhattisgarh), Anhoni and Salbardi (Narmada-Son region) |
| Eastern and western India | Bakreshwar (West Bengal), Rajgir (Bihar), Unkeshwar and Vajreshwari (Maharashtra) |
The Puga Valley in Ladakh is among the most promising sites for geothermal energy in India, and pilot projects have been planned there. The natural heat of the Earth, used as geothermal energy, can give steady power, heating and bathing resources, and it is among the clean sources of power discussed in Resources from the Ocean: Mineral Resources on the Deep Sea Floor, Energy Resources, Biotic Resources in the context of marine renewables.
How Do Geysers Differ from Hot Springs and Fumaroles?
| Feature | What comes out | Behaviour | Example |
|---|---|---|---|
| Geyser | Hot water and steam | Erupts at intervals; needs a narrow vent and water chamber | Old Faithful (Yellowstone), Strokkur (Iceland), El Tatio (Chile) |
| Hot spring | Warm to hot water | Flows steadily | Manikaran (Himachal Pradesh) |
| Fumarole | Steam and gases such as sulphur dioxide | Steady vent with little water | Valley of Ten Thousand Smokes, Alaska |
| Mud pot | Boiling mud | Acidic water dissolves rock into clay | Yellowstone, Rotorua (New Zealand) |
Geysers need three things together: a heat source, a good supply of groundwater and a plumbing of narrow channels. They are rare, found mainly in the USA (Yellowstone), Iceland, New Zealand, Chile and Russia (Kamchatka). Many were harmed by drilling and by tourism, and some have stopped erupting.
Why Do These Features Matter?
- Geothermal energy: hot springs and steam supply power and heating, as in Iceland, where most homes use geothermal heat. India has several geothermal fields, for instance Puga in Ladakh and Manikaran, which are being studied for power.
- Minerals and health: hot water carries dissolved minerals and is used in baths and treatments.
- Life: heat-loving microbes living in the hot pools gave clues to the origin of life, as in Origin of Life on Earth.
- Tourism: geyser fields and spa towns support local economies.
As an analytical point, geysers and hot springs show that heat sources remain below the surface even where no volcano erupts, and so they are used to find geothermal energy resources. The belts where they occur follow the regions in Distribution of Volcanoes: Pacific Ring of Fire, Mediterranean Volcanism.
Why Is This Topic Important?
- Examples Famous geysers are asked
- India Hot springs and geothermal sites
- Energy Geothermal resource
What Came Next?
The next topic explains how volcanoes are classed as extinct, dormant and active. Next topic: Extinct, Dormant and Active Volcanoes.
Key People and Terms
- Geyser Erupting hot spring
- Hot spring Spring of warm water
- Fumarole Steam and gas vent
- Mud pot Pool of boiling mud
- Crater Bowl at a volcano’s top
- Geothermal energy Heat from inside the Earth
Exam Corner
Points to Remember
- Old Faithful is in Yellowstone, USA.
- A geyser erupts periodically; a hot spring flows steadily.
- Iceland uses geothermal heat widely.
- Indian hot springs: Manikaran, Tattapani, Rajgir.
- A fumarole gives out steam and gases.
Do Not Confuse With
- Geyser and hot spring Intermittent versus continuous
- Fumarole and geyser Steam vent versus a water jet
- Crater and caldera Small summit bowl versus large collapse basin
Memory Hook
Geyser spouts, spring just flows; fumarole breathes, steam and gases.
Mains Angle
Questions ask for geothermal potential of India. These points add depth.
- Cause Heat plus groundwater
- Use Geothermal energy
- India Himalayan and peninsular hot springs
A Question You May Face
An original practice question, not a past paper question.
“Explain the formation of geysers and hot springs and discuss the geothermal energy potential of India.”
How to Answer
- Cause Heat and groundwater.
- Compare Geyser and spring.
- India Locations.
- Energy Potential and limits.
GS Relevance
Frequently Asked Questions
What is a geyser?
A geyser is a hot spring that periodically erupts a column of hot water and steam. It needs heat, water and a narrow plumbing system. Famous geysers include Old Faithful in Yellowstone, the Geysir in Iceland and those of El Tatio in Chile.
Where are the hot springs of India?
India's hot springs are found mainly along the Himalayas, such as Manikaran, Tapovan and Puga, along the Narmada-Son rift valleys, as at Tatapani, and on the west coast and in parts of eastern India, such as Bakreshwar and Rajgir.
What is the geothermal potential of India?
India has several hundred thermal springs grouped into geothermal provinces by the Geological Survey of India. The Puga Valley in Ladakh is considered among the best sites for geothermal power, though development in India is still at a pilot stage.
Where is Old Faithful geyser located?
Old Faithful is in Yellowstone National Park in the United States. It erupts about every 60 to 90 minutes, sending a jet of hot water and steam to a height of roughly 30 to 55 metres, and it is one of the best known and most predictable geysers in the world.
What is a fumarole?
A fumarole is an opening in the Earth's surface, usually near a volcano, that gives out steam and gases such as sulphur dioxide and carbon dioxide. It has little liquid water, unlike a hot spring or geyser. Fumaroles often leave deposits of sulphur around their vents.
PYQ Practice — Statement Analysis
1 Old Faithful is a geyser in Iceland.
It is in Yellowstone, USA.
2 A geyser erupts hot water and steam at intervals.
A hot spring flows steadily.
3 Iceland is a leading user of geothermal energy.
Many homes are heated by it.
4 Manikaran is a hot spring in Himachal Pradesh.
It lies in the Parvati valley.
Past Mains Questions on This Topic
This topic comes under Geomorphic Processes and Landform Evolution. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
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