Volcanic Ash and Vog

Question 1

What is volcanic ash?

Answer 1

Pulverized rock, volcanic glass

Question 2

What is the most widespread volcanic hazard?

Answer 2

Airborne volcanic ash

Question 3

What happens to ash in jet engines?

Answer 3

Melts, coats the turbine blades, may shut down engines

Question 4

What is 1 indicator that a dormant volcano might be “reawakening”?

Answer 4

Volcanic earthquakes

Question 5

What happened to a KLM flight in 1989?

Answer 5

Flew into Mt. Redoubt’s ash cloud, all 4 engines stalled, managed to start and landed safely in Anchorage

Question 6

Plate tectonic setting of Aleutian Islands

Answer 6

Active subduction zone = volcanoes and earthquakes

Question 7

Health Impacts on Citizens of Anchorage

Answer 7

• Can dmg lungs of small infants, elderly, infirm, or those already suffering from respiratory illnesses
• Ash cloud may reduce sunlight
• Heavy ash can clog watercourses, sewage plants, and various machinery
• Ash is heavy; can cause structural dmg to buildings
• Ash is extremely slippery, hampering both driving and walking

Question 8

How to protect yourself during ashfall

Answer 8

• Wear long sleeves and pants
• Use goggles to protect your eyes
• Wear glasses instead of contact lenses
• Use a dust mask or hold damp cloth over face to assist in breathing

Question 9

Eyjafjallajokull Volcano, Iceland

Answer 9

• In 2010, ash plumes caused major disruptions and grounded over 100k international flights, costing airlines >3.1bil
• Clouds of volcanic ash can spread across thousands of miles, depending on wind patterns and atmospheric stability, making them hard to predict

Question 10

What is a caldera? How are they formed?

Answer 10

A depression/large crater that forms when a magma chamber is emptied and collapses after a super eruption

Question 11

What is the diameter of Katla’s caldera?

Answer 11

10km

Question 12

When did Katla last erupt? How much bigger was this eruption than Eyjafjallajokull’s 2010 eruption?

Answer 12

Last erupted in 1918, 3x bigger than 2010 Eyjafjallajokull

Question 13

What is a potential sign of pressure building in Katla’s magma chamber? How is this being monitored?

Answer 13

Ground movement up and out/uplift on surface, monitored by GPS

Question 14

Plate Tectonic Setting of Iceland

Answer 14

• Located on the Mid-Atlantic Ridge
• Also a mantle plume/hot spot

Question 15

Vog conditions depend on

Answer 15

wind direction

Question 16

What is Vog?

Answer 16

A hazy mixture of SO2 gas and aerosols.
- Aerosols are created when SO2 and other volcanic gases combine in the atmosphere and interact with oxygen, moisture, dust, and sunlight over periods of mins to days
- Particulate matter (PM) in vog = PM2.5 because the particles are less than 2.5um in diameter and respirable particles
- Vog particles grow by absorbing water vapor and other gases, so they can increase in size in a moist environment ie human upper resp tract

Question 17

Symptoms from Vog

Answer 17

• Eye/nose/throat/skin irritation
• Coughing and/or phlegm
• Chest tightness and/or shortness of breath
• Increased susceptibility to respiratory ailments
• Fatigue and/or dizziness