Answer and Explanation: (b)
Ash
will travel the farthest from the vent. Volcanic eruptions often produce large amounts of ash that are released into the atmosphere.
What is the most hazardous volcanic hazard?
Lahars
are most dangerous close to a volcano, but large lahars may rapidly travel many tens of kilometres from a volcano, along river valleys, so they can pose a threat to people and infrastructure far beyond the volcano’s slopes.
What are the five volcanic hazards?
Several hazards may affect the area around the volcano, such as
lava flows, pyroclastic flows, lahars, jökulhlaups and landslides or debris avalanches
. Volcanic activity also produces hazards that can affect areas far from the volcano, such as tephra or ash falls, releases of gas and tsunamis.
How far do pyroclastic flows travel?
Pyroclastic Flows – can travel large distances from a volcano,
typically about 10 – 15 km, but sometimes up to 100 km
. Soufrière Type – the eruption column can no longer be sustained (due to loss of pressure), so the column collapses forming pyroclastic flows on the flanks of the volcano (St Vincent, 1902).
What kind of hazards are associated with volcanic eruptions?
The list of hazards associated with volcanic eruptions is long and varied:
lava flows, explosions, toxic gas clouds, ash falls, pyroclastic flows, avalanches, tsunamis, and mudflows
.
What are the main volcanic hazards which of these have the greatest potential to cause damage at large distances from the volcano?
Historically,
lahars
have been among the most destructive of all volcanic hazards, and they can travel long distances from their source. The deadly lahars at Nevado del Ruiz in 1985 were triggered when small pyroclastic flows abruptly melted snow and ice at the summit of the volcano.
Is carbon dioxide a volcanic hazard?
Carbon dioxide gas can collect in low-lying volcanic areas, posing a lethal risk to humans and animals
. A burning torch lowered into a CO2 pocket (top) causes the flame to go out (bottom). Magma contains dissolved gases, which provide the driving force that causes most volcanic eruptions.
How far do volcanic gases travel?
Bottom Line: Volcanic Ash Can Travel
10,000s of Miles
!
How far volcanic ash travels depend on a variety of factors, but ash from powerful volcanos have hovered in the atmosphere for years, traveling 10,000s of miles.
Why are volcanoes a hazard?
These gases include sulfur dioxide, carbon dioxide, hydrogen sulfide, and many others.
The release of gas can make a volcanic eruption more explosive, and some volcanoes produce large amounts of gas
. The gases can pose a variety of dangers to surrounding populations in sufficiently high concentrations.
How far can tephra travel?
Some large avalanches have been known to carry blocks as large as three kilometers in length, several kilometers from their source. Such avalanches can travel
close to 300 km h
− 1
(Francis, 1993).
How far can a volcanic eruption reach?
Helens or Pinatubo can reach high into the atmosphere. The highest Mt. St. Helens plume on May 18, 1980 reached about
31 km (101,700 feet)
, and the highest Pinatubo plume got as far as 45 km (147,600 feet).
What is the largest active volcano?
Rising gradually to more than 4 km (2.5 mi) above sea level, Hawaii’s
Mauna Loa
is the largest active volcano on our planet.
Can pyroclastic flows travel over water?
Pyroclastic flows can even move over water
. The 1815 eruption of Mount Tambora, Indonesia, is considered the largest volcanic eruption in recorded history. Its eruption column shot 40 kilometers (25 miles) into the atmosphere.
How far can lava travel from a volcano?
Viscous andesite flows move only a few kilometers per hour (couple feet per second) and rarely extend more than
8 km (5 mi)
from their vents. Viscous dacite and rhyolite flows often form steep-sided mounds called lava domes over an erupting vent.
Which of the following volcanic hazards are posed to the surrounding areas by Mount Rainier?
Debris flows (lahars)
pose the greatest hazard to people near Mount Rainier. A debris flow is a mixture of mud and rock debris that looks and behaves like flowing concrete. Giant debris flows sometimes develop when large masses of weak, water-saturated rock slide from the volcano’s flanks.
Which volcanic hazard poses the greatest threat to humans quizlet?
pyroclastic flows and lahars
are most dangerous to human life.
What is the tertiary effect of volcanic eruption?
Secondary effects: Effects of events triggered by the eruption. Tertiary effects:
Effects of long term or permanent changes brought about by the eruption
.
Is lapilli a volcanic hazard?
Lapilli is a size classification of tephra, which is
material that falls out of the air during a volcanic eruption or during some meteorite impacts
. Lapilli (singular: lapillus) is Latin for “little stones”. By definition lapilli range from 2 to 64 mm (0.08 to 2.52 in) in diameter.
Is mudflow a volcanic hazard?
Lahars transform the landscapes around Cascade Volcanoes.
Lahar is an Indonesian word describing a mudflow or debris flow that originates on the slopes of a volcano
. Small debris flows are common in the Cascades, where they form during periods of heavy rainfall, rapid snow melt, and by shallow landsliding.
Is fluorine a volcanic gas?
The volcanic activity represents the main natural persistent source of fluorine
that is emitted mostly in the form of HF.
