Lesson 2: Engineering Trade-offs

Key Idea

Detecting a tsunami requires specialized technology. Seismic sensors provide the fastest data by detecting ground shaking, but they cannot confirm if a wave has formed. Deep-water sensors (like DART buoys) measure pressure changes on the seafloor, offering high accuracy but coming with a high price tag.

Shallow-water sensors offer a cheaper alternative near the coast, though they provide very little warning time. Each sensor type functions differently, offering unique advantages regarding speed, cost, and information quality.

Key Idea

Perfect solutions are rarely achieved on the first attempt. Engineering relies on a process called iterative design, which involves cycling through steps: planning, building, testing, and analyzing.

Each test run in the TsunamiAlert simulation generates new performance data. Analyzing this data reveals weaknesses, such as a missed wave or a high cost. Engineers then modify the design—moving a sensor or changing a type—to improve performance in the next round.

Key Idea

Every design choice involves a compromise. Improving one aspect of a system often negatively affects another, a concept known as a trade-off.

For example, a network composed entirely of deep-water sensors maximizes accuracy but violates budget constraints. Conversely, a cheap system may produce too many false alarms. An optimal design does not maximize just one factor; it strikes the best possible balance between cost, speed, and reliability.