Paper 1 Unit 4: Tectonic Hazards

Comprehensive fill-in-the-blank practice flashcards covering Paper 1 Unit 4: Tectonic Hazards, including Earth structure, continental drift, plate boundaries, volcano and earthquake features, measurement scales, hazards, and disaster management strategies.

The revolutionary theory explaining that continents shift position on Earth's surface was proposed in 1912 by geophysicist and meteorologist __________.

Alfred Wegener

Oceanic crust is typically $5\text{--}10\,\text{km}$ thick, more dense than continental crust, and composed mostly of __________.

basalt

Continental crust is typically $30\text{--}50\,\text{km}$ thick, less dense than oceanic crust, and composed mostly of __________.

granite

The rigid outer layer of the Earth consisting of the crust and uppermost solid mantle is known as the __________.

lithosphere

The semi-molten lower part of the upper mantle upon which tectonic plates move is called the __________.

asthenosphere

At a __________ plate boundary, plates move apart, allowing magma to rise from the mantle and create shield volcanoes and new land.

constructive

At a destructive plate boundary, the heavier oceanic plate sinks beneath the continental plate into a __________ zone.

subduction

The __________ Fault in California is a prominent example of a conservative plate margin where two continental plates slide past one another.

San Andreas

The collision of the ancient rock of the Indian Plate into the Eurasian Plate led to the uplift of the __________ and Tibetan Plateau.

Himalayas

An isolated plume of rising magma originating from a particularly hot, static source in the mantle is called a __________.

hot spot

During an earthquake, __________ waves travel fastest through the Earth, causing an up-and-down longitudinal motion.

Primary (P)

The slower seismic waves that arrive second and move the ground from side to side with transverse motion are called __________ waves.

Secondary (S)

In the provided block diagram of earthquake features, the underground location where the earthquake energy is released and radiates outwards is called the __________.

Focus

The point on the surface of the Earth directly above the earthquake focus is the __________.

epicenter

A large underground pool of molten rock located beneath a volcano is known as the __________.

magma chamber

The illustrated volcano, characterized by gently sloping sides and formed by frequent, gentle eruptions of thin, runny lava, is a __________ volcano.

shield

The type of volcano shown, characterized by steep slopes above $10^\circ$ and alternating layers of lava and ash, is known as a __________ volcano.

composite

Small, steeply sloped volcanoes constructed from pyroclastic fragments that produce brief, explosive eruptions (e.g., Parícutin) are called __________ volcanoes.

cinder cone

A volcano that has not erupted for many years but still shows evidence of an active magma reservoir is classified as __________.

dormant

Volcanic particles measuring less than __________ in diameter are classified as volcanic ash.

$$2\,\text{mm}$$

Any fragmented volcanic material ejected into the atmosphere during an eruption is broadly termed __________.

tephra

Extremely fast-moving clouds of superheated gas and ash that can travel up to $500\,\text{km/h}$ and reach temperatures over $700^\circ\text{C}$ are called __________.

pyroclastic flows

Secondary volcanic mudflows formed when hot ash and gas melt snow and ice on volcanic slopes are known as __________.

lahars

People who accept living in hazardous environments because they view the dangers as inevitable and lack alternatives due to poverty hold a __________ viewpoint.

fatalistic

When people choose to reside near hazard zones after deciding through a cost-benefit analysis that advantages outweigh disadvantages, this viewpoint is termed __________.

acceptance

Workers endure hazardous conditions at the crater lake of the Ijen volcano in Indonesia to mine __________ from the lake floor.

sulphur

The updated logarithmic scale that measures the total energy released by an earthquake based on the area of fault slip is the __________ Scale.

Moment Magnitude

Because earthquake magnitude scales are logarithmic, a magnitude 6 earthquake has __________ times more ground shaking than a magnitude 5 earthquake.

$$10$$

The scale numbered 1 to 10 that measures earthquake intensity based on observed structural damage and human perception is the __________ Scale.

Mercalli

Volcanic explosive magnitude is measured using the __________, which ranks eruptions on a logarithmic scale from 0 to 8.

Volcano Explosivity Index (VEI)

A secondary earthquake hazard where saturated, loose soil and rock behave like a liquid under seismic shaking is called __________.

soil liquefaction

A primary earthquake hazard that occurs when deep fault slip breaks directly through the surface of the ground is known as __________.

surface rupture

In the standard earthquake drill sequence illustrated in the diagram, the three essential steps are '__________, Cover, Hold On!'.

Drop

During an earthquake drill, individuals using a walker or wheelchair are instructed to '__________! Cover! Hold On!'.

Lock

In the earthquake-resistant high-rise building diagram, the base is isolated from ground motion using __________ to absorb earth tremors.

rubber shock-absorbers

In the self-anchored suspension span of the Oakland Bay Bridge, the four sections of the tower are connected by __________ designed to flex or break during seismic shocks.

shear links

Earthquake early-warning systems detect the rapid arrival of __________ waves using seismometer sensors spaced $6\text{--}12\,\text{miles}$ apart.

P

In the provided 'Phases of Disaster' diagram, the high-cohesion community phase occurring within the first one to three days is the __________ phase.

Honey-moon

Hazard mitigation measures such as hazard mapping and risk assessments that aim to reduce future impacts are categorized as __________ responses.

long-term