Exam 5: Tsunami

Cowell's Cove is a beach in Santa Cruz, California noted for good surfing. The Santa Cruz coastal area is in the form of a broad (5 km) short (1.5 km) bay, facing south. ​ On the west side of the beach is a long (1 km) raised peninsula with a steep rocky cliff edge. The top is about 5 m above the water level. Behind the peninsula, the ground rises in a neighborhood of twisty, one-lane streets to a level 15 m above sea level. The nearest stairway is about 100 m away. To the east, the beach is flat leading to a popular tourist boardwalk. Your car is parked behind the boardwalk about 200 m away. Behind this area a straight two-lane road goes through the downtown area for about 5 km before reaching Highway 101 and hilly country. ​ The sea is calm and flat except for a regular line of clean surf breaks surf breaks about 1 m high along the peninsula. You feel a slight jolt. Some rocks tumble from the cliffs, and you can hear car horns honking at areas along the beachfront. After looking around for a few minutes, you notice that the edge of the water is receding quickly, and hear sirens from emergency vehicles in some directions. ​ Assume that you are physically fit, and that your car is in good working order. What do you do? Explain your reasoning.

A tsunami in Japan would affect ____.

As a tsunami enters a bay or fjord, wave height ____.

As the first wave of a tsunami retreats from the shore, bystanders should expect a second wave within approximately ____.

A tsunami _______________ is issued when an earthquake of magnitude 7 or greater is detected somewhere around the Pacific Ocean.

Compared to wind-driven waves, tsunami waves have ____.

A(n) _______________ landslide occurs underwater and may cause a tsunami.

The linear distance between two wave crests is the _______________ of the tsunami.

The series of tsunami generated in a single offshore event will impact the coastline for a period of several ____.

Tsunami effects are increased by ____.

When a tsunami wave passes an island surrounded by shallow water, ____.

The difference between tsunami watches and tsunami warnings is that ____.

The _______________ of a volcano can collapse and slump, triggering a tsunami as a debris avalanche distributes material along the seafloor.

Direct evidence of giant tsunami is found in ____.

Evidence of past tsunami can be seen in the _______________, a line across a mountainside separating taller and shorter trees.

Giant tsunami are usually the result of _____.

Tsunamis cannot be caused by ____.

Structures can mitigate tsunami damage, but vegetation cannot.

The _______________ is the height that a tsunami reaches as it rushes onshore.

A ship at sea will not generally notice the passage of a tsunami wave because they ____ in the deep ocean.