SOLVED

11) ________ are not associated with a mid-ocean ridge. A) Very thin, ocean floor, sediment layer B) Submarine basaltic lava eruptions C) Shallower depths than abyssal plains D) Deep ocean trenches 12) ________ is (are) not part of an ophiolite complex. A) Basaltic lavas and pillow lavas B) Residual, unmelted, crustal lithosphere C) Intrusive, coarse-grained gabbro D) Steeply inclined, basaltic dikes 13) Where in the oceans are biological communities thriving without sunlight? A) in shallow water, coral reefs B) in muds of deep-ocean trenches C) around seafloor, hot spring vents D) around fissure vents for flood basalts 14) A(n) ________ is a low lying, coral reef island perched above a sunken, truncated volcano. A) guyot B) seamount C) fringing reef D) atoll 15) ________ proposed a correct theory of how atolls formed. A) Isaac Newton B) Charles Darwin C) James Hutton D) Charles Lyell 16) ________ are highly detrimental to healthy growth of coral reefs. A) Clear, sunlit waters B) Nutrient-rich waters with luxuriant algae growth C) Warm water temperatures D) Vigorous wave action and water circulation 17) ________ is the oceanward edge of a continental shelf. A) The deepest portion of a deep-ocean trench B) The top of the abyssal plain C) The base of the continental rise D) The top of the continental slope 18) Geologically, what is the best way to explain the thousands of feet of coral limestone beneath most atolls? A) Sea level has fallen thousands of feet since the reef began to grow. B) An eroded volcanic seamount rose thousands of feet after the limestone formed. C) The eroded volcano slowly sank as sea level remained steady or rose gradually. D) The volcano never reached the surface, allowing a very thick cap of coral limestones to accumulate. 19) The continental rise is located ________. A) at the top of a mid-ocean ridge B) at the top of the continental slope C) between an abyssal plain and continental slope D) at the seaward edge of a deep ocean trench 20) An echo sounder operates by measuring the time required for a ________. A) light beam to travel from a satellite at a known altitude to the sea bottom and back B) radar beam to travel from a harbor patrol boat to a fuzz-buster on a speeding yacht C) radar beam to travel from a ship to the seafloor and back D) sound pulse travels from a ship to the seafloor and back 21) Oceans cover approximately ________ of Earth’s surface area? A) 10% B) 90% C) 50% D) 70%