Tsunami Alert Systems Worksheet
Futura Geohazards Engineering Internship
Chapter 4: Tsunami Warning Systems
Dossier Comprehension
Student Name:
Date:
Period:
Score: /18
Engineering Directive: Read Chapter 4 (pages 10–12) of your Geohazards Dossier. Answer each question carefully using facts, data tables, and sensor specifications provided by Futura.
PART 1
Multiple Choice Questions (1–5)
Select the best answer for each question.
- Why are tsunami warning systems especially vital for ocean-wide tsunamis compared to local tsunamis?
A Ocean-wide waves only travel across shallow coastal reefs.
B Distant coastal populations feel no earthquake shaking to alert them.
C Ocean-wide waves travel much slower than local waves.
D Local tsunamis never cause physical destruction or flooding.
- What do earthquake sensors directly measure?
A Changes in ocean water pressure on the seafloor.
B Rising water height at piers and harbor walls.
C Earth's shaking, including magnitude and location.
D The speed of moving water waves across the surface.
- Where must deep ocean sensors be installed according to the dossier?
A On floating buoys near shallow beaches.
B Attached directly to harbor piers and docks.
C On the seafloor in deep ocean water.
D Exclusively on land stations near subduction zones.
- Why do earthquake sensors have low data reliability for confirming tsunamis?
A They detect shaking, but not all earthquakes cause tsunamis.
B They take many hours to transmit initial data.
C They break almost every time an earthquake happens.
D They cannot operate if placed on the seafloor.
- Why do shallow ocean sensors have a "long delay" in sending tsunami data?
A Their computer wiring loses power during storms.
B The tsunami wave must physically reach the shoreline or pier.
C They must verify earthquake magnitude before recording water levels.
D They are located thousands of miles out in deep ocean trenches.
Futura Geohazards Engineering Internship • Chapter 4 Assessment Page 1 of 3
Chapter 4: Tsunami Warning Systems
Futura Engineering Dossier
PART 2
Multiple Answer Questions (6–8)
Select ALL correct options that apply (two or more).
- According to the dossier, what costs contribute to the total 50-year expense of a warning system? (Select all that apply)
Buying and purchasing the physical sensors Installing sensors on land, seafloor, or piers Maintaining equipment over multiple decades Replacing sensors when they break from wear or quakes
- What conditions can cause ocean sensors (shallow or deep) to generate false alarms? (Select all that apply)
Sending data for a small, local tsunami to faraway places not at risk A nearby earthquake causing a pressure change without a tsunami wave Normal ocean tides naturally rising and falling every 12 hours Sensors communicating in Spanish instead of English
- How do warning center scientists adjust their decisions based on sensor reliability? (Select all that apply)
With a highly reliable sensor, they may only need data from one other sensor. With less reliable sensors, scientists wait for data from additional sensors. They ignore all sensor data and rely only on eyewitness phone calls. They evaluate both how much data arrived and which sensor types sent it.
PART 3
True or False Statements (9–13)
Circle T for True or F for False.
- Shallow sensors can detect both earthquake activity and ocean surface level shifts.
T F
- A local tsunami wave only reaches coastal areas closest to the earthquake that triggered it.
T F
- Deep sensors have the highest data reliability, but they cost the most and break often.
T F
- Earthquake sensors installed on the seafloor cost the exact same as earthquake sensors placed on land.
T F
- People living on the opposite side of an ocean usually feel the earthquake shaking before a wave arrives.
T F
Futura Geohazards Engineering Internship • Chapter 4 Assessment Page 2 of 3
Chapter 4: Tsunami Warning Systems
Futura Engineering Dossier
PART 4
Matching Component Roles (Question 14)
Write the letter of the correct description next to each item.
Warning System Components
14a. Earthquake Sensor
14b. Shallow Sensor
14c. Deep Sensor
14d. Warning Center
Operational Descriptions
A. Installed on the deep seafloor; measures water pressure shifts as waves pass over; excellent tsunami indicator.
B. Receives networked sensor data, interprets reliability patterns, and issues evacuation alerts to vulnerable coastlines.
C. Placed on land or seafloor; measures Earth's shaking magnitude and location with very short delay; cannot detect waves.
D. Placed near shores or attached to piers; measures ocean surface level changes; has long data delay.
PART 5
Ranking & System Analysis (15–18)
Apply data from the Chapter 4 summary table.
15. Ranking Sensor Cost: Rank the four sensor setups from LOWEST purchase cost (1) to HIGHEST purchase cost (4) based on the summary table.
Deep Sensor
Shallow Sensor
Earthquake (Land)
Earthquake (Seafloor)
16. Ranking Data Delay: Rank the three sensor types from SHORTEST transmission delay (1) to LONGEST transmission delay (3).
Shallow Sensor
Earthquake Sensor
Deep Sensor
17. Process Sequencing: Number the steps from 1 to 4 in the chronological order of how a tsunami warning system operates.
Computers at warning centers receive environmental sensor data.
An underwater earthquake shakes the seafloor and displaces water.
Scientists interpret sensor reliability and issue evacuation alerts.
Sensors detect ground shaking and ocean water pressure changes.
18. Engineering Trade-Off Analysis: A design team proposes using only deep sensors because they have high data reliability. Based on the dossier, what major trade-off must they accept?
A Deep sensors cannot transmit any data across ocean water.
B Highest purchase cost ($$$$$) and frequent breakage requiring costly replacement.
C Deep sensors have a much longer transmission delay than shallow sensors.
D Deep sensors can only be installed in shallow water near piers.
Futura Geohazards Engineering Internship • Chapter 4 Assessment Page 3 of 3
Tsunami Alert Systems Answer Key
Futura Geohazards Internship • Teacher Resource
Chapter 4 Answer Key & Teacher Guide
18 Points Total
Textbook Alignment: Chapter 4: Tsunami Warning Systems (Pages 10–12) Grading Standard: 1 point per numbered item (1–18)
PART 1
Multiple Choice Solutions (Questions 1–5)
1 pt each • 5 pts total
1. Ocean-wide vs. local tsunami warning necessity
Correct: B
Dossier Reference: Page 10, paragraph 1.
Rationale: People close to the earthquake feel ground shaking and can head inland instinctively. Distant populations across the ocean feel no shaking at all and have no visual or tactile warning without technological detection systems.
2. What earthquake sensors directly measure
Correct: C
Dossier Reference: Page 11, "Earthquake Sensor".
Rationale: Earthquake sensors detect seismic shaking, magnitude, and distance/epicenter location. They cannot measure ocean water height or detect whether water was displaced into a tsunami wave.
3. Deep sensor installation location
Correct: C
Dossier Reference: Page 11, "Deep Sensor".
Rationale: Deep sensors must sit directly on the seafloor in deep ocean water to measure hydro-static water column pressure variations as tsunami crests pass overhead.
4. Low reliability of earthquake sensors for tsunamis
Correct: A
Dossier Reference: Page 10, paragraph 4 and Page 11.
Rationale: A strong earthquake can shake sensors without causing vertical plate subduction or seafloor displacement; assuming an earthquake always causes a tsunami triggers false alarms.
5. Cause of "long delay" in shallow sensors
Correct: B
Dossier Reference: Page 11 and summary table on Page 12.
Rationale: Shallow sensors are located near shores or on harbor piers. Because they only sense water surface elevation, they cannot transmit warning data until the wave has traveled all the way from the deep ocean origin to the coast.
Futura Geohazards Internship • Teacher Answer Key Page 1 of 3
Chapter 4 Answer Key: Parts 2 & 3
Futura Engineering Dossier
PART 2
Multiple Answer Solutions (Questions 6–8)
1 pt each (all correct required)
