Hazard Risk Estimates - Middle School Earth and Space Science
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Which option indicates higher risk: high likelihood/low impact or low likelihood/high impact?
Which option indicates higher risk: high likelihood/low impact or low likelihood/high impact?
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Either can be higher; compare both likelihood and impact together. Risk depends on both factors multiplied together.
Either can be higher; compare both likelihood and impact together. Risk depends on both factors multiplied together.
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What is the formula for annual probability using recurrence interval $T$ (years)?
What is the formula for annual probability using recurrence interval $T$ (years)?
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$P=\frac{1}{T}$. Probability equals one divided by the recurrence interval.
$P=\frac{1}{T}$. Probability equals one divided by the recurrence interval.
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State the formula for annual probability using recurrence interval $T$ (years).
State the formula for annual probability using recurrence interval $T$ (years).
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$p = \frac{1}{T}$. Annual probability equals one divided by recurrence interval.
$p = \frac{1}{T}$. Annual probability equals one divided by recurrence interval.
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What is the meaning of recurrence interval (return period) for a hazard?
What is the meaning of recurrence interval (return period) for a hazard?
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Average time between events of a given size at a location. Longer intervals mean rarer events; shorter intervals mean more frequent.
Average time between events of a given size at a location. Longer intervals mean rarer events; shorter intervals mean more frequent.
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Calculate annual probability when a flood has recurrence interval $T = 50$ years.
Calculate annual probability when a flood has recurrence interval $T = 50$ years.
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$p = \frac{1}{50} = 0.02$. Substitute $T = 50$ into formula $p = rac{1}{T}$.
$p = \frac{1}{50} = 0.02$. Substitute $T = 50$ into formula $p = rac{1}{T}$.
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Which option best describes a hazard frequency graph where higher magnitude is rarer?
Which option best describes a hazard frequency graph where higher magnitude is rarer?
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Frequency decreases as magnitude increases (inverse relationship). Larger events are less frequent than smaller events.
Frequency decreases as magnitude increases (inverse relationship). Larger events are less frequent than smaller events.
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Choose the correct comparison: same impact, higher likelihood means what risk change?
Choose the correct comparison: same impact, higher likelihood means what risk change?
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Risk increases. Higher likelihood with same impact means greater overall risk.
Risk increases. Higher likelihood with same impact means greater overall risk.
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Identify the recurrence interval $T$ if the annual probability is $P=0.1$.
Identify the recurrence interval $T$ if the annual probability is $P=0.1$.
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$T=\frac{1}{0.1}=10$ years. Inverse of 0.1 probability gives 10-year average interval.
$T=\frac{1}{0.1}=10$ years. Inverse of 0.1 probability gives 10-year average interval.
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Which metric best represents hazard frequency in a data table: event count per decade or maximum damage?
Which metric best represents hazard frequency in a data table: event count per decade or maximum damage?
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Event count per decade. Frequency measures how often events occur over time.
Event count per decade. Frequency measures how often events occur over time.
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Calculate the mean annual rate if $12$ floods occurred in $60$ years in a town.
Calculate the mean annual rate if $12$ floods occurred in $60$ years in a town.
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$\frac{12}{60} = 0.2$ floods per year. Divide total events by time period: $\frac{12}{60} = 0.2$ per year.
$\frac{12}{60} = 0.2$ floods per year. Divide total events by time period: $\frac{12}{60} = 0.2$ per year.
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Which statement best describes what a fault “slip rate” helps estimate?
Which statement best describes what a fault “slip rate” helps estimate?
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How often large earthquakes may occur on that fault. Faster slip rates mean more frequent large earthquakes.
How often large earthquakes may occur on that fault. Faster slip rates mean more frequent large earthquakes.
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What does a hazard map color with the highest category usually represent?
What does a hazard map color with the highest category usually represent?
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Areas with the greatest expected hazard level or probability. Darker colors show zones with highest hazard levels.
Areas with the greatest expected hazard level or probability. Darker colors show zones with highest hazard levels.
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What is the event rate per year for $12$ hurricanes in $40$ years?
What is the event rate per year for $12$ hurricanes in $40$ years?
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$0.3$ hurricanes per year. Rate = events ÷ time period = $12 ÷ 40$.
$0.3$ hurricanes per year. Rate = events ÷ time period = $12 ÷ 40$.
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Identify the higher risk if losses differ: A has $p=0.05$, $L=\$100{,}000$; B has $p=0.01$, $L=$800{,}000$.
Identify the higher risk if losses differ: A has $p=0.05$, $L=\$100{,}000$; B has $p=0.01$, $L=$800{,}000$.
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B (A: $\$5{,}000$; B: $$8{,}000$ expected loss per year). Compare expected losses: A gives $5,000/yr, B gives $8,000/yr.
B (A: $\$5{,}000$; B: $$8{,}000$ expected loss per year). Compare expected losses: A gives $5,000/yr, B gives $8,000/yr.
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Find and correct the statement: "A 100-year flood happens exactly every 100 years."
Find and correct the statement: "A 100-year flood happens exactly every 100 years."
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Correct: It has $p=\frac{1}{100}$ each year; timing is not fixed. Common misconception: events are random, not periodic.
Correct: It has $p=\frac{1}{100}$ each year; timing is not fixed. Common misconception: events are random, not periodic.
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What is the annual probability for an event with return period $T$ years?
What is the annual probability for an event with return period $T$ years?
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$p=\frac{1}{T}$ per year. Inverse relationship: longer return period means lower annual probability.
$p=\frac{1}{T}$ per year. Inverse relationship: longer return period means lower annual probability.
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What does return period mean in hazard statistics (for example, a 100-year flood)?
What does return period mean in hazard statistics (for example, a 100-year flood)?
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Average time between events of a given size or larger. Statistical average, not a guaranteed interval between occurrences.
Average time between events of a given size or larger. Statistical average, not a guaranteed interval between occurrences.
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What is the difference between hazard, risk, and vulnerability in natural-disaster data?
What is the difference between hazard, risk, and vulnerability in natural-disaster data?
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Hazard: event; risk: expected harm; vulnerability: susceptibility. Hazard is the event itself, risk includes probability and consequences.
Hazard: event; risk: expected harm; vulnerability: susceptibility. Hazard is the event itself, risk includes probability and consequences.
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What does a steep slope on a frequency–magnitude graph usually indicate?
What does a steep slope on a frequency–magnitude graph usually indicate?
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Large events become much rarer as magnitude increases. Power-law relationship typical of many natural hazards.
Large events become much rarer as magnitude increases. Power-law relationship typical of many natural hazards.
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What does a hazard map color scale typically represent (for example, seismic hazard shading)?
What does a hazard map color scale typically represent (for example, seismic hazard shading)?
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Relative likelihood or intensity level (higher color = higher hazard). Visual representation helps identify high-risk areas for planning.
Relative likelihood or intensity level (higher color = higher hazard). Visual representation helps identify high-risk areas for planning.
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What is exposure in risk assessment for hazards such as floods or wildfires?
What is exposure in risk assessment for hazards such as floods or wildfires?
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People and property located in the hazard zone. First component of risk assessment: what could be affected.
People and property located in the hazard zone. First component of risk assessment: what could be affected.
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What does expected annual loss (EAL) represent in hazard-impact estimation?
What does expected annual loss (EAL) represent in hazard-impact estimation?
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Average loss per year when probability and damage are combined. Useful for insurance and long-term planning decisions.
Average loss per year when probability and damage are combined. Useful for insurance and long-term planning decisions.
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What does a hazard map typically show for a region (in one phrase)?
What does a hazard map typically show for a region (in one phrase)?
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Areas of different hazard levels (likelihood or expected intensity). Maps use colors or contours to show spatial variation in hazard levels.
Areas of different hazard levels (likelihood or expected intensity). Maps use colors or contours to show spatial variation in hazard levels.
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Which option best describes frequency in hazard data: size/energy or how often it happens?
Which option best describes frequency in hazard data: size/energy or how often it happens?
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How often events occur in a given time period. Frequency counts occurrences per unit time, not event strength.
How often events occur in a given time period. Frequency counts occurrences per unit time, not event strength.
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Identify the higher risk: Site A high hazard/low exposure or Site B moderate hazard/high exposure.
Identify the higher risk: Site A high hazard/low exposure or Site B moderate hazard/high exposure.
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Site B. High exposure amplifies risk more than high hazard with low exposure.
Site B. High exposure amplifies risk more than high hazard with low exposure.
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