Answer to Question 1
True
Answer to Question 2
The Pacific coast is an actively rising margin on which volcanoes, earthquakes, and other indications of tectonic activity are easily observed. Pacific coast beaches are typically interrupted by jagged rocky headlands, volcanic intrusions, and the effects of submarine canyons. Marine terraces are found as much as 400 meters (1,300 feet) above sea level in a number of places. Most of the sediments on the Pacific coast originated from erosion of relatively young granitic or volcanic rocks of nearby mountains.
The Atlantic coast is a passive margin, tectonically calm and subsiding because of its trailing position on the North American Plate. Subsidence along the coast has been considerable-3,000 meters (10,000 feet) over the last 150 million years. A deep layer of sediment has built up offshore, material that helped produce today's barrier islands. Relatively recent subsidence has been more important in shaping the present coast, however, With the exception of the coast of Maine, coastal sinking and rising sea level have combined to submerge some parts of the Atlantic coast at a rate of about 0.5 meter (1 foot) per century.