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GNR 639 : Natural And Management

Disasters related to

Land – Geological

• • Earthquake • Land subsidence • • Snow avalanche

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And ManagementGNR 639

Volcano • What is it? • Causes • What happens • Where does it occur? • Indicators? • Monitoring • Prevention • Vulnerability • Preparedness?

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And ManagementGNR 639 It is circular mountain (crator) through which hot molten is erupted out.

It may active, dormant or dead

In addition to magma, ash, gases, and hot debris are also thrown into atmosphere

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And ManagementGNR 639

Volcano is a vent for the molten rock or magma to reach the earth's surface from a reservoir of molten matter.

The material ejected through the vent frequently accumulates around the opening, building up a cone, called the volcanic edifice.

Volcanic eruptions vary between two extremes.

There are many different kinds of volcanic activity and eruptions: pheratic eruptions (stream); explosive eruption of high silica content in (rhyolite); effusive eruption of low silica lava (); pyroclastic flows; (); and carbon dioxide emission Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Distribution of Volcanoes in different countries Country Volcano USA Cold Bay Volcano (Alaska), Novarupta (Alaska), Mount St. Helens (Washington), Mount Baker (Washington), (Washington), Mount Hood (Oregon), (California), Kilauea (Hawaii), Mauna Kea (Hawaii), (Hawaii),

Japan Mount Fuji (Honshu) Antarctica Mount Erebus (Ross Island,) Italy Etna (Sicily), (Bay of Naples) Iceland Krafla, Hekla, Surtsey Grenada Kick-'em-Jenny Russia Kluchevskaya (Kamchatka) Krakatoa (Rakata), Tambora (Sumbawa) Peru El Misti (Arequipa) Philippines (Luzon Island) Mexico Mexico-Puebla state line Greece (Santorini islands) Spain (Tenerife, Canary Islands,) New Zealand White Island (Bay of Plenty) Soufriere Hills volcano, (Montserrat) India Barrren Island Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Volcanoes erupted in the past 1586 Kelut, Indonesia – caused 10.000 deaths 1631 Vesuvius, Italy – caused 3.500 deaths 1772 Papandayan, Indonesia – caused 3.000 deaths 1783 Asama, – caused 1.377 deaths 1783 Laki, Iceland – 9.350 deaths, most due to starvation 1792 , Japan – caused tsunami and 14.300 deaths 1815 Tambora, Indonesia – 92.000 deaths, caused by starvation and disease 1882 Galunggung, Indonesia – caused 4.000 deaths 1883 Krakatau, Indonesia – caused tsunami and 36.417 deaths 1902 Mount Pelée, West Indies – devastation of St. Pierre and 40.000 deaths 1919 Kelut, Indonesia – caused 5.110 deaths 1951 Lamington, – caused 3.000 deaths 1963 Aguna, Indonesia – caused 1.184 deaths 1982 El Chichon, Mexico – caused 2.000 deaths 1985 Nevado del Ruiz, Columbia – deadly mudflow, 25.000 deaths 1991 Mount Unzen, Japan 1994 Rabaul, Papua New Guinea 1997 Soufrière Hills, Montserrat, West-Indies 2004 Manam, Indonesia – 10.000 people evacuated, most still living in temporary camps

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639Recent : Natural Volcanic Disaster eruptions And Management GNR 639

Eruption Start Country / 2009 Nov Costa Rica Poás Volcano Date Location 2008 Oct 26 Colombia Huila, Nevado del 2011 Iceland Grímsvötn 2008 Sep 19 Solomon Is Tinakula 2011 Chile Puyehue-Cordón Caulle 2008 Jul 27 Ecuador Reventador 2011 Chile Planchón-Peteroa 2008 May 23 Vanuatu Ambrym 2011 Costa Rica Turrialba 2008 Apr 5 Indonesia Ibu 2011 Nicaragua Telica 2005 Apr 15 United Kingdom Soufrière Hills 2011 Russia Kliuchevskoi 2005 Jan 9 México Popocatépetl 2011 Russia Bezymianny 2004 Oct 23 Japan Suwanose-jim 2011 Japan Aso 2002 May 17 DR Congo Nyiragongo 2011 Japan Kirishima 2002 Jan 4 Guatemala Fuego 2011 Indonesia Karangetang Api Siau) 2001 Nov 15 Russia Karymsky 2011 Indonesia Lokon-Empung 2000 Sep 16 Papua New Guinea Bagana 2011 Eritrea Nabro 1999 Aug 15 Russia Shiveluch Dec 15 2010 Nicaragua San Cristóbal 1997 Nov 22 México Colima Nov 26 2010 Indonesia Tengger Caldera 1972 Dec East Antarctica Erebus Nov 22 2010 Ecuador Tungurahua Nov 11 2010 Russia Kizimen 1967 Aug 31 Indonesia Semeru Nov 6 2010 Philippines Bulusan 1967 (in or before) Ethiopia Erta Ale Oct 25 2010 Indonesia Krakatau 1955 Oct 13 Japan Sakura-jima Sep 17 2010 India Barren Island 1934 Aug 8 Ecuador Sangay Aug 25 2010 Italy Etna 1934 Feb 2 Italy Stromboli Aug 10 2010 Papua New Guinea Manam 1933 Aug 13 Indonesia Dukono May 26 2010 Papua New Guinea 1922 Jun 22 Guatemala Santa María Dec 11 2009 Nicaragua Concepción 1774 (in or before) Vanuatu Yasur 2009 Nov 22 Chile Villarrica Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster• Tectonic And PlateManagement Boundaries

(Source courtesy: usgs.gov) ~75% world’s active volcanoes in Ring of Fire Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 GNR 639 : Natural Disaster And Management

Continental plates (Source courtesy: learner.org) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Movement of tectonic plates

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And ManagementGNR 639

Earth’s interior • Compositional layers – 0 – 100 km (silicates) • Mantle : 100 – 2900 km (silicates) • Core : 2900 – 6370 km (iron, Nickel)

Mechanical layers • Lithosphere : 0 -100 km (rigid) (Source courtesy: spring8.or.jp) • Asthenosphere : 100 – 350 km (soft plastic) • Mesophere: 350 – 2900 km (liquid) • Inner core: 5100 – 6370km

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: hiddeninearth.blogspot)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: scribal.com)

Submarine volcanoes are underwater vents or fissures from which magma erupts (75% of annual magma output). They are located near areas of tectonic plate movement, known as ocean ridges. (Courtesy: nbcnews.com) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Eruption of Kavachi Volcano, an undersea volcano located off the coast of the .

(Source courtesy: nasa) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: smore.com) (Source courtesy: blomberg.com)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy: the-earth-story.com) Source courtesy:theboldcorsicanflame.wordpress

Mud volcanoes

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Source courtesy:intechopen.com

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Parts of a volcano

Source courtesy: http://www.enchantedlearning.com/subjects/volcano/gifs/volcanodiagram.GIF

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

VENT- the vent is the opening from which lava flows. Dust, ash, and rock particles can also be thrown out of the vent

Crater- It is a funnel shaped pit. It is formed when the material explodes out of the vent

Volcanic cone- is the pile of lava, dust, ashes, and rock around the vent. It can be found in different shapes

(Source courtesy: ranker.com)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: houstonchronicle.com)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: goeddelphotograph.com) Source courtesy:pmel.noaa.gov

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

(Source courtesy: news.softpedia.com)

Prof. R. Nagarajan, CSRE , IIT Bombay Precursor to GNR 639 : Natural Disaster And Management Pompeii (79AD) Pyroclastic flows of poisonous gas and hot volcanic debris engulfed the cities of Pompeii, Herculaneum and Stabiae suffocating the inhabitants and burying the buildings.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Volcanic lake, Phillipines

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Barren island volcano

Source courtesy: poleshift.mog.com

Source courtesy:volcano.si.edu

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Barren island volcano

First recorded eruption in 1787, further eruptions were recorded in 1789, 1795, 1803–04, and 1852. After nearly one and half century of dormancy, the island had another eruption in 1991 that lasted six months and caused considerable damage. There were eruptions in 1994–95 and 2005–07, the latter considered to be linked to the 2004 Indian Ocean earthquake

The highest elevation on the island is 354 m , with most of the primitive volcano underwater (standing on the seafloor 2,250 metres below sea level). The island is 3 km in diameter, with a total surface area of 10 km2

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Barren island volcano

Source courtesy: volcano.si.edu

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Magma Types • Composition:

Magmas: >Fe, Mg (mafic) vs >SiO2 (felsic) Felsic (, Rhyolite) >63%) of silica Viscous form lava domes. Intermediate composition 52–63% of silica. Mafic lava <52% and >45% silica and higher percentages of Mg and Fe.

• Dependent on tectonic setting Ocean spreading ridges and hot spots: Mafic rocks (basalt) Continental rifts: felsic (rhyolite, ) Subduction zones: mafic + felsic

• Volcanic Gases: CO2, SO2 Pressure builds up as rises to surface

Felsic (more SiO2): viscous + thick = explosive Mafic (less SiO2): fluid, gases escape

Prof. R. Nagarajan, CSRE , IIT Bombay Volcanic Fatalities

• 92,000 Tambora, Indonesia 1815 • 36,000 Krakatau, Indonesia 1883 • 29,000 Mt Pelee, Martinique 1902 • 15,000 Mt Unzen, Japan 1792

Courtesy of www.swisseduc.ch But, volcanoes cause fewer fatalities than earthquakes, hurricanes and famine. GNR 639 : Natural Disaster And Management GNR 639 Types of volcano Shield - wide and somewhat flat. Lava flows out quietly and for great distances. Cinder Cone - tall, very steep sides. Explosive eruptions produce a lot of cinder and ash. Composite - small, with steep sides, explosive eruptions, produce a lot of lava and ash. Seafloor Spreading Ridges, Fissure Eruptions Volcanic Domes Cinder Cones Composite Volcanoes

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Volcanic eruption types ( Source: Macdonald 1972) Type Characteristics Icelandic Fissure eruption that quietly release large volumes of free flowing (fluid) basaltic magma which is poor in gas and which flows as sheets over large areas and builds up plateaus. Minor amounts of Tephra. Hawaiian Fissure, caldera and pit crater eruptions; mobile lavas with some gas in thin, fluid flows; quiet to moderately active eruptions; occasional rapid emission of gassy lava in fountains; only minor amounts of ash; builds up lava domes. Strombolian Stratoconds (summit craters);moderate, rhythmic to nearly continuous explosions, resulting from spasmodic gas escape; clots of lava ejected, as bombs and scoria; periodic, thicker outpourings of moderately fluid lava; light-colored clouds(mostly steam) reach upwards only moderate heights.

Vulcanian Stratocones (central vents);viscous lavas in short, thick flows; lavas crust over in vent between eruptions, allowing gas to build up below surface; eruptions increase in violence and are interspersed with longer quiescent periods until lava crust is broken up, clearing vent and ejecting bombs, and ash; lava flows out of summit after main explosive eruption; dark, covoluted and cauliflower-shaped ash-laden clouds, rising to moderate heights more or less vertically, depositing ash along flanks of volcano(In Pseudo-vulcanean eruptions phreatic steam clouds vent fragmental matter explosively.)

Surtseyan Violently explosive, Phreato-magmatic eruption, ejecting fragmental material and glassy Tephra. Vesuvian More paroxysmal than preceding types; extremely violent expulsion of gas-charged magma from stratocone vent; eruption occurs after long interval of of quiescence or mild activity; vent tends to be emptied to considerable depth; lava ejects in explosive spray (glowing above vent) with repeated clouds that reach great heights and deposit ash. Plinian More violent form of Vesuvian eruption; sometimes associated with caldera collapse; last major phase is uprush of gas that carries clouds rapidly upward in vertical columns that are narrow at their bases but are kilometers high and expand outward at upper altitudes; wide dispersal of tephra, including pumice; cloud is generally low in ash. The largest kinds of explosive eruption are known as ultra-plinian or krakatoan. Pelean Results from high viscosity lavas, delayed explosiveness; conduit of usually blocked by dome or plug; gas (some lava)escaped from flank openings or by destruction or uplift of plug; gas, ash and blocks move down slope in one or more blasts as nuees' ardentes or other forms of , producing directed deposits.

Bandaian Collapse of part of volcanic edifice, producing massive landslide or rock avalanche. Katmaian Voluminous production of ignimbrites(welded tuff deposits)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Volcanic Explosivity Index (VEI) (USGS)

Volcanic Explosivity Qualitative Classification Tropospheric Stratospheric Explosivity description injection injection Index 0 Non-explosive Effusive Hawaiian Negligible None 1 Small Gentle Hawaiian Strombolian Minor None 2 Moderate Explosive Strombolian Moderate None 3 moderate- Severe Strombolian, vulacanian Great Possible large 4 large Violent Vulcanian, Plinian Great Definite 5 Very large Cataclysmic Plinian, Ultraplinian Great Significant 6 Very large Paroxysmal Ultraplinian Great Significant 7 Very large Colossal Ultraplinian Great Significant 8 Very large Terrific Ultraplinian Great significant

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management Volcanic Explosivity Index

Source courtesy: dailymail.co.uk

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Volcanic process characteristics and mitigation (Source: McGuire, 1998) Volcanic process Characteristics and mitigation Lava flows Lava flows generally move slowly, along paths determined by topography and do not normally threatens life. It cause destruction through burial and burning, and this may end all existing land use, preventing it being re-established for many centuries. Mitigation measures include: general & specific prediction; damming and/or diversion and slowing the flow using water-cooling. Domes Domes are formed when magma is too viscous and immobile to flow very far. Pyroclastic flows may be generated by collapse. Pyroclastic falls Pyroclastic falls range in size from ash (less than 2 mm), lapilli (2mm*(69 mm) to blocks/bombs (greater than 64 mm). Falls present a number of hazards. Near to the volcano, failure of roofs, power lines and cables and death and injury through the impact of large size blocks and bombs, may occur. Ash can destroy vegetation, crops, block roads, and clog drains, watercourses and cause damage to equipment. In large eruptions, the dangers to aircraft may be considerable and particles can be spread over the globe and impact on climate and weather. Mitigation measures include: general and specific prediction; pre-eruption evacuation; measures to ensure that the roofs of buildings are of sufficient strength; provision of face masks and uncontaminated water; and warnings to air traffic.

Lateral (directed) Lateral blasts are highly destructive. Blasts kill by heat, burial and impact. Blasts are caused by decompression of magmatic gases, or explosion of high pressure hydrothermal systems. blasts Blasts involve ballistic action from ashes, blocks and bombs, and may also include pyroclastic surges and flows. Blasts often cause the partial destruction of the volcanic edifice. Examples include: Bezymianny (Russia, 1956) and Mt. St Helens (USA, 1980). Gases Volcanic gases present hazards to the health and may damage vegetation. The effects of gases are at their most severe near to a volcano and wind directions are important in determining distribution. In large eruptions, gases may have an impact on global climate. Mitigation measures include: general and specific prediction; re-settlement if persistent, and pre-eruption evacuation if transient. Pyroclastic flows Pyroclastic flows are hot dry masses of particulate volcanic material that move along the ground surface. Maximum temperatures in pyroclastic flows range from 3303C to more than 5503C. Flows are mobile and travel at speeds of over 100 kmh-1. On eroded volcanoes, flows are restricted to valleys if thin, but on lowlands may be deposited as fans. Flows are very hazardous. Flows of modest size were associated with Krakatau (Sunda Straits, 1883) and Katmai (Alaska, 1912) and are relatively low frequency events, but if one did occur in a densely populated area, then it would cause one of the greatest of human . Around many volcanoes there are thin deposits that cover large areas. These are thought to be emplaced by very high velocity flows, which can surmount high mountain barriers. Even smaller flows, of which there are many historic examples (e.g. Mont PeleHe and La Soufrie`re*Caribbean 1902), constitute a very serious hazard and would cause death and destruction to all in their paths. Mitigation measures include: general and specific prediction; judicious siting of settlements and pre-evacuation.

Pyroclastic surges A surge is a turbulent, low density cloud of gases and rock debris, perhaps accompanied by water and steam that moves at high speed. Two sub-types are recognized: (a) Hot surges are very dangerous and can cause death, injury, destruction of buildings, impact damage and burial. Hot surges move at great speed and may be formed by a number of processes (e.g. explosive disruption of domes, collapse of domes, collapse of eruption columns and lateral blasts); (b) Cold surges are associated with hydrovolcanic eruptions and are produced by vertical explosions and by material falling from eruption columns. Temperatures are usually below 10030 C. Normally surges are confined to within 10km of their source. Surges kill and injure, destroy structures through burial and impact. Mitigation measures are similar to those for flows. Pyroclastic flows and Pyroclastic surges may be regarded as the end members of a relatively continuous range of flow types.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Hazards from • Lava • Pyroclastics (rocks and lava) • Lahars (mudflow of ash and water) • Pyroclastic Flows–Glowing cloud • Toxic Gases • Steam Explosions • Secondary Effects: Climate and Atmospheric Chemistry

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Volcano-related hazards and measures of mitigation (McGuire, 1998) Process Characteristics and mitigation Lahars and Floods Flooding is often associated with volcanoes with crater lakes, and in situations where eruptions occur beneath snow and ice. When concentrations of sediment increase then a may be generated. Lahar to include all sediment/water mixtures, e.g. mudflows, debris flows etc, then these may be generated in a number of ways. (a) Rapid melting of snow and ice. (b) By an avalanche, induced by an eruption, depositing material into a stream or lake. (c) By a lava or pyroclastic flow moving into a stream or lake. (d) By a volcanic earthquake inducing slope failure and initiating mass movement. (e) By heavy rains on a volcano. (f) Sub-glacial eruptions. (g). Breaching of a crater lake. Lahars have in the past caused substantial damage and catastrophic loss of life Lahars may travel distances of up to 300km from their sources at speeds of around 100kmh-1 and are concentrated in and follow existing valleys and topographical depressions. Mitigation measures include: planning and evacuation based on general and specific prediction, judicious siting of settlements and sediment dams. Collapse Structural collapse of volcanoes to form calderas and major sector collapses are rare, but examples are known (e.g. San volcano (Japan, 1888) and Tenerife, at least 9 sector collapses and 3 caldera collapses are recognized). Tsunami may also be initiated if collapse takes place near to the sea. Collapses represent a high potential hazard, but one with a long recurrence interval. Debris avalanches are generated by the collapse of part of a volcanic edifice, e.g. Unzen (Japan, 1792). Run-out distances of studied avalanches range from less than 10km to over 50 km. Mitigation measures include: general and specific prediction and pre-eruption evacuation. Deformation and earthquakes Some volcanoes inflate before eruptions as magma is stored e.g. before the 1980 eruption of Mount St. Helens an elliptical area moved outwards at 2m/day for nearly six weeks. Magma intrusion at shallow depth without eruption (e.g. Campi Flegrei, Italy 1982}4) also causes ground inflation. The major hazards are seismic effects on buildings and evacuation is often required. Tsunami Volcano induced tsunami have not been a major cause of death in the twentieth century, but in earlier centuries their effects were catastrophic. Examples include: Unzen Volcano (Japan 1792); Krakatau (Sunda Straits between Sumatra and Java 1883) and Tambora (Indonesia 1815). Volcanoes in coastal locations may induce tsunami through a variety of processes which include: (a) violent explosion (e.g. Krakatau); (b) a landslide into the sea (e.g. Unzen) and (c) sector collapse. All volcanoes near to the sea have the capacity to generate tsumanis. Mitigation measures include those listed for collapse and tsunamis warning networks. Other hazards Include: starvation; epidemic disease; contamination of water and land; drowning; transport accidents; exposure; cardiac arrests and the breakdown of law and order. Most of these are preventable given good civil defence.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Impacts of volcanic eruption

( source Courtesy:worldlywise.pbwise.com) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Dispersion of and gas in troposphere Source courtesy: global-greenhouse-warming.com Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Source courtesy: wready..org

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Impact of volcanic eruptions Eruptive event Consequences Health impact Preventative measures Explosions Lateral blast, rock Trauma; skin burns, Evacuation minimization fragments air shock Lacerations from broken of exposure to flying glass waves windows Hot ash release Nuees' ardentes ash Skin and lung burns, Evacuation flows and falls, Asphyxiation, Llightning Electrocution Melting ice, snow Mudflows, floods Engulfing, Drowning Evacuation, or rain Diversion barriers accompanying eruption Lava Lava flow, Engulfing and burns (rare) Evacuation, Forest fires Diversion barriers Gas emissions: Pooling in low-lying Asphyxiation, Evacuation, Breathing

CO, CO2, HF, HS, areas and inhalation Constriction of the apparatus for geologists SO2 airways Radon Radiation exposure Lung cancer Evacuation Earthquakes Building damage trauma Evacuation, anti-seismic construction

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Indicators of volcanic eruption

• Detectable earthquakes • Short-period earthquakes signify the growth of a magma body near the surface and are known as 'A' waves. • Long-period earthquakes indicate increased gas pressure in a volcano's plumbing system (water hammer). 'B' waves are also known as resonance waves and long period resonance events. • Harmonic tremors are often the result of magma pushing against the overlying rock below the surface • Deformation of the ground surface • An increased rate of swelling, especially if accompanied by an increase in sulphur dioxide emissions and harmonic tremors is a high probability sign of an impending event. • Changes in the temperature and chemistry of the groundwater and spring waters.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Upward movement of magma

(Source courtesy: Indiana.edu)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy:iris.edu) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy:pnsn.org)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy: geochemicalperspectivesletters.org)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Remote sensing Cloud sensing: monitor the unusually cold eruption clouds from volcanoes using two different thermal wavelengths to enhance the visibility of eruption clouds and discriminate them from meteorological clouds. Gas sensing: Sulphur dioxide are measured by TOMS (Total Ozone Mapping Spectrometer) Thermal sensing: The presence of significant thermal signatures indicate new heating of the ground before an eruption, represent an eruption in progress or the presence of a very recent volcanic deposit, including lava flows or pyroclastic flows. Deformation sensing: Satellite-borne spatial radar data detect long-term geometric changes in the volcanic edifice, such as uplift and depression. InSAR (Interferometric Synthetic Aperture Radar), DEMs generated from radar imagery are subtracted from each other to yield a differential image, displaying rates of topographic change. Forest Monitoring: location of eruptive fractures could be predicted, months to years before the eruptions, by the monitoring of forest growth. Acoustic Flow Monitors (AFM) is used to analyze ground tremors that could result in a lahar(mud flow), providing an earlier warning

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Landsat satellite image and an elevation model from the Shuttle Radar Topography Mission (SRTM) to provide a view of Nyiragongo Volcano and the city of Goma Democratic Republic of Congo.

(Source courtesy: nasa earth observatory) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy: geowarn.ethz.ch)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Satellite image showing the Chaitan Volcanic eruption, Chile

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management Thermal imaging of volcano

(Source courtesy: asterweb.jpl.nasa)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Hydrology

•Borehole and well hydrologic and hydraulic measurements to monitor changes in a volcanoes subsurface gas pressure and thermal regime. Increased gas pressure make water levels rise and drop, and local heat flow reduce or dry out aquifers.

•Detection of lahars and other debris flows close to their sources.

•Pre-eruption sediment may be picked up by a channel is an indication of morphological changes and increased hydrothermal activity.

•Volcanic deposit can dramatically widen or deepen the river channel.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Seismic Activity • Earthquake activity commonly precedes an eruption as the result of magma pushing up towards the surface • Increase volume of material in the volcano shatters the rock causes earthquakes • Seismographs positioned on the flanks of the volcano record the frequency, duration and intensity

Deformation Monitoring • Tiltmeters are used to measure the deformation of the volcano • It measures the changes in slope as small as one part per million.

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Anomalous heat flow

• forward looking infrared radiometry (FLIR) installed on-site, at a distance, or airborne • Infrared band satellite imagery; • in-situ thermometry (hot springs, fumaroles) • heat flux maps • geothermal well enthalpy changes

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639 Gas Monitoring • Gas output from a volcano increases or changes composition before an eruption. • Rising magma releases (exsolves) much of its gas content. • Gas samples are collected from fumaroles and active vents. • Gas levels may also be monitored by remote sensing techniques

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Source courtesy: scielo.org.mx

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

63 Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Source courtesy: volcano.si.edu)

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management GNR 639

Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

(Source courtesy: volcano.si.edu) Prof. R. Nagarajan, CSRE , IIT Bombay GNR 639 : Natural Disaster And Management

Source courtesy: caloes.ca.gov

Prof. R. Nagarajan, CSRE , IIT Bombay