Explaining and Forecasting

4.A Apply scientific ideas to construct an explanation for how sudden changes in the ocean floor during an earthquake lead to the formation of a tsunami.

4.A Apply scientific ideas to construct an explanation for how sudden changes in the ocean floor during an earthquake lead to the formation of a tsunami.

Students should make connections that when sudden shifts in the ocean floor form a tsunami, it can move quickly across the ocean and cause damage when it reaches the coastlines. They should use scientific ideas of how waves move and qualitative variables such as relative distance to the epicenter and local shoreline topography to rank order the risk of four places, determine which place needs immediate action, and determine where tsunami-mitigation funds should be prioritized.

If students struggle in developing explanations and/or ranking the risk of different places, call attention to supports embedded in the assessment, such as pictures and descriptions. Also consider these prompts to help their sensemaking:

Remind students to support their claims with evidence from their Tsunami Chain of Events poster and observations made during the first 3 lessons of the unit.

Provide sentence stems (on a sheet of chart paper) to help students write a claim supported by evidence. For example, “Place ___ is most at risk for damage from a tsunami. I know this because __________.”

Remind students that damage resulting from a tsunami is associated with the loss of lives and properties; they should consider the potential people and property that might be impacted in each place.

Use Scoring Guidance for Explaining and Forecasting Tsunami Risk to help you assess students’ ability to construct an explanation that describes how sudden geologic forces (i.e., an earthquake) in the ocean floor can cause a tsunami, how different communities may be at varying risk of damage, and which communities should be prioritized for tsunami mitigation resources.