Volcanoes for Online Quiz PDF

**Volcanoes** - are the vents or earth's opening where molten rock material and volcanic gases are erupted from within Earth's interior, - Volcanoes are mountains but they\'re very different from other mountains, they\'re not formed by folding and crumpling or by uplift and erosion...

**Volcanoes** - are the vents or earth's opening where molten rock material and volcanic gases are erupted from within Earth's interior, - Volcanoes are mountains but they\'re very different from other mountains, they\'re not formed by folding and crumpling or by uplift and erosion. - Volcanoes are built by the buildup of their own eruptive products \-- lava, bombs (crusted over ash flows, and tephra (airborne ash and dust). - A volcano is most ordinarily a conical hill or mountain built around a vent that connects with reservoirs of molten rock below the surface of the planet. **Ash**- small parts of lava or rocks which are shot in the air by explosions **Vent** -- the opening in the volcano from where lava comes out. (throat) Volcanoes have several shapes, which are controlled by the composition of the magma and therefore the nature if its eruption. +-----------------------------------+-----------------------------------+ | - **Cinder Cone Volcano** | - **Shield Volcano** | +-----------------------------------+-----------------------------------+ | - **Composite Volcano** | - **Lava Volcano** | +-----------------------------------+-----------------------------------+ 1. - It is also called *[as scoria cone]*. Is that the simplest, most typical type, and features a characteristic conoid. - It forms when volcanic cinder, blobs of congealed lava of basaltic composition, comes out from one vent. its explosive eruptions caused by gas rapidly expanding and escaping from the molten lava that comes out sort of a fountain. - The lava cools quickly and falls as cinders that build up round the vent forming a round shape, leaving a crater at the summit. - These volcanoes will be as high as 100 to 400 meters, because the lava is blown violently into the atmosphere, it breaks into small fragments, solidifies and falls as a cinders round the vent. - **Shape** : bowl-shaped / oval shape - **Lava Type**: basaltic lava (enriched in iron and magnesium and depleted in silica) - **Viscosity**: Less viscous, quite fluid. - **Examples**: Paricutín in Mexico, Taal in Philippines as the lava is blown violently into the atmosphere, it breaks into small fragments, solidifies and falls as a cinders around the vent. 2. - Also observed as strato-volcanoes, it includes a number of the world's grandest mountains. - A tall conical mountain composed of an alternating layer of lava-flow, which justifies the name composite volcano. - It can have a cluster of vents, with lava breaking through walls or issuing from fissures on the perimeters of the mountain. The eruptions are extremely explosive and dangerous. - Pressure builds within the magma chamber as gases under immense heat and pressure are dissolved within the magma. - When the magma reaches the vents, the pressure is released, and also the gases explode violently. These is up to 100 to 3500 meters high. - **Shape** : cone-shaped / conical with concave shape - **Lava Type**: Rhyolitic lava (high content of silica and low iron and magnesium contents) - **Viscosity** : Highly viscous that hardens before it can spread far. - **Examples**: Fujiyama in Japan, Mt. Mayon and Kanlaon in Philippines 3. - Shield volcanoes are huge, gently sloped volcanoes that just about exclusively erupts basaltic lava and include a number of the biggest volcanoes within the world. - It\'s built by many layers of ***[low-viscous]*** lava flows. - The eruptions don\'t seem to be explosive; the lava oozes out from the central vent or a gaggle of vents and spreads far, building a dome shape profile sort of a warrior's shield. - They will be as high as 9000 meters from the bottom. - **Shape**: domical-shaped / flat-rounded shape - **Lava Type**: basaltic lava - **Viscosity**: Less viscous, quite fluid - **Examples**: The volcanoes within the Hawaiian Island, including Kilauea, 4. - It is also referred to as volcanic dome. These are relatively small, circular mounds formed because the lava is simply too viscous to flow, which makes it piles over and round the vents, because the lava oozes out, its outer surface cools and hardens, then shatters, spilling loose fragments down its side. - Lava domes are found within the crater or on the edges of enormous composite volcanoes. - Their height depends on the dimensions of the composite volcanoes they seem around. - **Shape** : domical shape / dome shaped - **Lava Type:** rhyolitic lava - **Viscosity**: Highly viscous, less fluid - **Examples**: There are lava domes within the crater of Mount St. Helens, Chaitén lava dome, Lassen Peak 1. 2. 3. 1. - have a recent history of eruption. - are those that have a record of volcanic activity such as, rumbling, crater glow or eruption and earthquakes within the last 600 years or those that erupted 10,000 years ago based on analysis of volcanic deposits. **Example**: - **Mt. Mayon** ( in Albay) , - **Mt. Taal** (in Batangas) - **Mt. Pinatubo** ( in boundaries of Pampanga, Tarlac and Zambales, - **Mt. Matutum** in Cotabato 2. - are volcanoes that have not erupted for a very long period of time but may erupt at a future time. - Are morphologically young-looking and are suspected to generate seismic activities. - Mt. Apo in Davao del Sur - Mt. Arayat in Pampanga - Mt. Panay in Batangas 3. - Are volcanoes that are not expected to erupt in the future. - Refer to volcanoes which have no historical records of eruption and are severely weathered and eroded. - Sampaloc Lake in Laguna - Mt. Guiauasan in Biliran - Mt. Kitanglad in Bukidnon **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** **Main Idea**: A volcanic eruption can change Earth's topography **EQ**: Why should you keep yourself informed about volcanic activities? **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** **Volcanic Eruptions** - Is the eruption or expulsion of gases, rock fragments, and / or molten rock from within the Earth through a vent (volcano) onto the Earth's surface or into the atmosphere. - caused by ***magma*** (a mixture of liquid rock, crystals, and dissolved gas) that is accumulated in the magma chamber under the volcano that is expelled onto the Earth\'s surface. - ***[Gas]** gives magmas their explosive character because the volume of gas expands as pressure is reduced* - - Mostly water vapor & some carbon dioxide a. **Phreatic or hydrothermal Eruption**- *[An eruption driven by the heat from]* - Phreatic eruptions pulverize surrounding rocks and can produce ash, but do not include new magma. b. **Phreatomagmatic Eruption**- - *[An eruption resulting from the interaction]* *[of new magma or lava with water and can be very explosive]*. The water can be from groundwater, hydrothermal systems, surface runoff, a lake, or the sea. Example: submarine volcanoes (some) like **Surtsey Volcano in Iceland**. **Taal Volcano in Batangas** c. **Strombolian Eruption -- *[is violent, marked by a continuous ejection of ]*** ***[magma and gas].*** - ***[It has explosions causing a shower of lava fragments.]*** - *[It results in the formation of volcanic bombs and **cinder cones**].* d. **Hawaiian Eruption**- *is [the least violent types of explosive eruptions] with* - Hawaiian eruptions *[have fire fountains and lava flows.]* e. **Vulcanian Eruption-** are small to moderate explosive eruptions, lasting - *Viscous magma flows out of volcano's vent[, accompanied by a dense cloud of ash and gases that rises high into atmosphere].* f. **Plinian**-[The most violent, explosive and largest type of volcanic ] - [It is caused by buildup of magma and dissolved gas.] - Are characterized by large ash columns and fast flowing pyroclastic flows and lahars - Eruptions with a high rate of magma discharge sustained for minutes to hours. They form a tall, convective eruption column of a mixture of gas and rock particles and can cause wide dispersion of ash. - Plinian eruptions have 20 to 35 km tall columns which may collapse to form pyroclastic density currents (PDC's).   ***[Factors affecting the Nature of Volcanic Eruption and Volcanic cone]*** 1. Temperature of Magma 2. Chemical Composition of Magma 3. Amount of dissolved gases in magma. *Note : these factors can affect the viscosity magma in different ways.* **VISCOSITY**: *is the property of the material's resistance to flow.* - described as the thickness and stickiness of a liquid. - Important property in determining the eruptive behavior of magmas. 1. **Temperature of Magma** - **The viscosity of magma decreases with temperature.** - **The higher the temperature of magma, the lower its viscosity.** 2. **Chemical Composition of Magma** - **Magmas with high silica content are more viscous than those with low silica content.** - **Magmas that contains less silica is relatively fluid and travels far before solidifying.** ***Types of Magma based on their chemical composition:*** 3. **Amount of Gas Dissolved in Magma** - **Gas (mainly water vapor) dissolved in magma tends to increase its ability to flow.** - - - - the gas dissolved in magma affects it viscosity. *Note: the more gas escape out of magma, the more the viscosity increases.* *The amount of gas in magma is related to the chemical* *composition of the magma. Basaltic magmas usually have lower gas* *contents than rhyolitic magmas.* **[Temperature of various magmas]:** - Basaltic magma - 1000 to 1200^o^C - Andesitic magma - 800 to 1000^o^C - Rhyolitic magma - 650 to 800^o^C.   **Summary Table 1. Magma Composition and Characteristics** +-----------+-----------+-----------+-----------+-----------+-----------+ | **Magma | **Chemica | **Gas | **Explosi | **Tempera | **Viscosi | | Type** | l | Content** | veness** | ture** | ty** | | | Compositi | | | | | | | on** | | | | | | | | | | | | | | **(silica | | | | | | | content)* | | | | | | | * | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | Basaltic | 45-55 | Low | Least | 1000-1200 | Least / | | Magma | SiO~2~ % | | | ^0^C | low | | | **high** | | | | | | | in Fe, | | | | | | | Mg, Ca, | | | | | | | **low** | | | | | | | in K, Na | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | Andesitic | 55-65 | Intermedi | Intermedi | 8000-1000 | intermedi | | Magma | SiO~2~ % | ate | ate | ^0^C | ate | | | **interme | | | | | | | diate** | | | | | | | in Fe, | | | | | | | Mg, Ca, | | | | | | | K, Na | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ | Rhyolitic | 65-75 | high | greatest | 650-800 | Most / | | Magma | SiO~2~ % | | | ^0^C | highly | | | **low** | | | | | | | in Fe, | | | | | | | Mg, Ca, | | | | | | | | | | | | | | **high** | | | | | | | in K, Na | | | | | +-----------+-----------+-----------+-----------+-----------+-----------+ ***A volcanic eruption is the expulsion of gases, rock fragments, and/or molten lava from within the Earth through a vent onto the Earth's surface or into the atmosphere.*** ***[Processes or Steps:]*** 1. slowly melt and become a thick flowing substance called magma. It is comprised of molten lithospheric rocks, as well as gases and water vapor 2. and builds up in underground reservoir called magma chamber. 3. 4. 5. 6.  **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** **Main Idea**: Volcanoes pose hazards that can be mitigated **EQ**: How does one prepare for volcanic eruption **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** **Commonly known Hazards of a Volcanic Eruption** 1. **Blasts** - *These are bursts of trapped, hot gases that push their way through solid barriers, within Earth\'s crust and rapidly into the atmosphere.* 2. **Dome growth** - *This refers to a mound of lava that grows inside the crater*, called a *[cryptodome]*. If it grows outside the volcano, it is called an exodome, which may collapse and release large volumes of molten material into the environment. 3. **Gases** - Among the gases released by active and inactive volcanoes are water vapor (H₂O), hydrogen sulfide (H,S), sulfur dioxide (SO₂), hydrogen chloride (HCI), hydrogen fluoride (HF), hydrogen (H), and carbon dioxide (CO₂). Other gases include nitrogen (N₂), methane (CH),argon (Ar), and helium (He). These gases are potentially hazardous to all life-forms. 4. **Lahar** - *This is also called mudflow or flow of volcanic debris*. Lahars can be classified into **[two types]**: *[primary or hot lahar]* associated directly with the eruption, and *[secondary or cold lahar] flow*, which occurs during heavy rainfall. 5. **Lava flow** - *This refers to the molten rocks that are released by volcanoes or volcanic vents.* The viscosity of the lava and the steepness of the volcano slope can influence the rate of lava flow. Lava with high viscosity flows at a rate of 0.25 km/hr, while lava with low viscosity flows at 45 km/hr. Lava flows faster down steep slopes and moves slower over more level terrain. 6. **Pyroclastic flow** - *This refers to the flow of glowing hot material that moves down the slope of an erupting volcano*. Pyroclasts, which come from the Greek words pyro (fire) and last (broken), are rock fragments that are ejected during volcanic eruptions. 7. **Pyroclastic surges** -*These are dense, fast-moving masses of gases, ash, rock fragments, and water extruded ejected during some volcanic eruptions.* 8. **Tephra falls** - *These may consist of combinations of pumice, scoria (basalt), thick rock fragments, and crystals, whose sizes range from 2 mm in diameter (ash) to more than 64 mm in diameter (blocks).* 9. **Tsunami** - *Tsunamis are series of water waves caused by the displacement of large volumes of water because of an underwater earthquake or volcanic eruption.* **Destructive Effect of Volcanoes / Volcanic Eruption** 1. **Loss of lives** 2. **Loss of properties** 3. **Destruction of crops** 4. **Destruction of wild life habitat** 5. **Towns and cities get buried under lava and volcanic rocks** **Benefits from Volcanoes /Volcanic Eruption** 1\. Volcanoes are good sources of geothermal energy. 2\. The pyroclastic materials and lava flows coming from volcanoes are rich in minerals which make the soil fertile, enabling farmers to cultivate healthier and better crops. 3\. Valuable minerals such as aluminum, gold, nickel, lead, zinc, and copper can be extracted from volcanic materials. 4\. New islands may be formed. 5\. These new islands may then become potential habitat for pioneer species of plants and animals. 6\. Volcanoes can encourage tourism and generate income for the local community. 7\. Hot springs are formed from volcanic activity and are areas for relaxation and scenic beauty. **Disaster Preparedness** The **Philippine Institute of Volcanology and Seismology** **(PHIVOLCS**) has prepared a list of things to do before a volcanic eruption and during a volcanic eruption. **[BEFORE a Volcanic Eruption]** 1. Prepare an emergency go bag containing the items you will need during a disaster, including: 2. If you live near a volcano, secure maps that show possible path of volcanic flows. 3. Create an escape or evacuation plan and plot the safest routes to nearby evacuation centers. Avoid low-lying areas and those in the direct path of lava flow or mudflow. **[DURING a Volcanic Eruption]** 1. Stay indoors. 2. If you are driving to an evacuation center, drive slowly and carefully. 3. Close the windows, doors, air conditioners, and other vents during an ash fall. 4. Wear protective gear-goggles and gas masks, long pants, and long-sleeved tops. 5. Avoid inhaling volcanic dust. Cover your face with a wet towel to help you breathe. 6. Heed government orders for evacuation if you live near the erupting volcano. 7. Tune in to the radio for advisories and warnings. 8. Help neighbors who may need special assistance. **After a volcanic eruption** 1. 2. 3. 4. 5. 6. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_  **Energy from Volcanoes** **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** **Main Idea**: Geothermal energy is the heat from within the Earth. **EQ**: How do you benefit from the energy within Earth? **\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--** Earth is believe to be extremely hot from within, as you go deeper down the Earth, its temperature increases. For every kilometer you go deeper, the temperature increases by an average of 25°C (Turgeon, 2012; Donev, et al. 2019). The heat generated within the Earth is called ***geothermal energy***. **Philippines** is situated along the ***[Pacific Ring of Fire]***. We have about 300 volcanoes in our country (Santos, 2020). The abundance of volcanoes and earthquakes satisfies the conditions for geothermal resources. **What is Geothermal Energy?** **Geothermal Energy** -- - comes from the Greek words, ***geo*** meaning "*earth*" and ***therme*** meaning "*heat*". - It is a renewable energy that can that is enclosed in the rocks and fluids beneath the earth's crust and can be found as far down to the earth's hot molten rock, **magma**. - Is the heat energy from the earth's interior. **How is geothermal energy generated?** **Geothermal energy is generated in [two (2) ways:]** 1. 2. These two ways of generating energy differ in the depth of heat source to produce energy. 1. **Geothermal Power Plants-** the heat from deep inside the Earth is used to produce **Steps how geothermal power plant works (EPA 2017):** 1. 2. 3. 4. 5. 6. 2. **Geothermal Heat Pump** -use the heat near the Earth\'s surface to heat water or - **Heat pumps** *are machines that use a refrigeration cycle like the refrigerator*. Heat is transferred by pumping water or a refrigerant through underground pipes where they absorb heat. 1. When the weather is cold, water moves through the loops of pipes underground. 2. The water heats up when it travels through the loop. 3. When the warmed water moves above ground, it transfers heat into the building. 4. The water cools down after heat is transferred. It is once again pumped underground, and the process starts again. 5. 6. When the weather is hot, the system works in the opposite, where the water in the pipes is warmed from the heat in the building then it is pumped underground to transfer the heat to the ground. The cool water then moves above ground to begin the cycle again.  In the Philippines, geothermal power plants are used to generate electricity in Tiwi (Albay), Kidapawan (North Cotabato), Calaca (Laguna), Tongonan (Leyte), Bago City (Negros Occidental), Valencia (Negros Oriental), and Bacon (Sorsogon). The figure 14 below shows the Mak-Ban Geothermal Power Plant in Laguna.