CRISES OF A PLANET - GEOL 108FIRST TEST BANK (example questions)TRUE/FALSE (2 points each) The Earth never experienced the same heavy meteorite cratering of the moon at 4.5 to 4.7 b.y. because most of meteorites were burned up in the thick atmosphere.The terrestrial planets, including Mercury, Venus, Earth and Mars, are enriched in iron, magnesium, silicon, and oxygen relative to the larger more distant planets.Heating of the inner portions of Earth result from fusion of hydrogen atoms. Planet Earth had no atmosphere at the time of its formation.A sample from Saturn, if brought back to Earth, would be much heavier than any common Earth rock.The universe is expanding today.The Solar System is expanding today.The age of light coming to earth from the most distant regions of the universe dates back to about 12 to 14 b.y. ago, the estimated age of the "Big Bang".The internal energy within the Earth is derived from radioactive decay.It is reasonably certain that the initial crust of the Earth was of basaltic composition.The core, mantle, and crust of the earth were formed during its initial aggregation 4.7 billion years ago.The density of the outer planets is similar to that of water.The residual high temperatures left from the Earth's initial accretion caused internal melting and segregation to begin the process of differentiation forming core, mantle, and crust.The concept of the hydrologic cycle implies that most water is of magmatic origin, with the principal cycling occurring at the ocean ridges and subduction zonesThe fluid motion of the outer core is the cause of the Earth's magnetic field. Ocean crust only appears to be made of rocks less than 200 million years in age as all older crust is buried under a thick layer of abyssal mud.The Earth's early atmosphere resulted from volcanic activity.The outer core of the earth is mostly comprised of molten iron.Early earth destroyed its crust much like is occurring in the oceans today. Life on Earth began in a continental rift. The core of the earth formed from impact of iron meteorites. Water on planet Earth initially arrived from comets. Island arcs result from convergence of two ocean plates.Subduction zone earthquakes range in depth from shallow at the trench to several hundred kilometers beneath the overriding plate. Ocean crust only appears to be made of Mesozoic or younger rocks as all older crust is buried under a thick layer of abyssal mud.Heating of the inner portions of Earth result from fusion of hydrogen atoms.Although the average age of the Earth is 4.6 billion years (b.y.), rocks older than 4.6 b.y. occur inthe continental interiors and rocks younger than 4.6 b.y occur on the continental margins.Pangea formed from a number of continental collisions leading to the formation of the Ural and Appalachian Mountains.Ocean crust is youngest at the ocean ridges where it is formed and becomes progressively older with distance from the ridge.The longest mountain range of the Earth is mostly underwater.Ocean trenches result from rifting.Transform faults connect ends of offset ocean ridges.Primary waves cause the first shaking in an earthquake.The greater the distance to an earthquake epicenter, the longer the time period between arrival of primary and secondary waves.Without radioactivity the Earth would be a dead planet. Excluding the effects of immigration, the 1995 U.S. population growth rate of 0.69 % indicates that the country’s population was decreasing during this period of time.Whereas the population of our planet reached the first billion mark near the year 1830, today's population is approximately 6 billion with an additional billion added in increasingly shorter periods of time. Both the Red Sea and the Gulf of California are the recent result of rifting and sea-floor spreading.Convergence of two ocean plates leads to the construction of island arcs such as the Aleutians, the Tonga Islands, and Japan.Rifting of Pangea resulted in the formation of Laurasia and Gondwanaland.The present site of the Ural Mountains represents the demise of a long-lost ocean basin.Without subduction, there would be no continental crust.The focii of subduction zone earthquakes range in depth from shallow at the trench to several hundred kilometers beneath the overriding plate. Transform faults connect ends of offset ocean ridges.Sedimentary rocks at the bottom of a geocline are as old as the initial rifting that formed the ocean basin.As early as 1911, Alfred Wegener presented ideas about sea floor spreading.California is destined to sink into the ocean.The Earth's magnetic poles have wandered extensively thorough geologic time.Ocean crust becomes progressively younger away from the ocean ridges.Continents are incapable of rifting due to their great thickness and mass.The San Andreas fault is a boundary between the North American and Pacific plates, the latter presently moving northward toward the Aleutian trench.The only rocks found on the Earth's surface having an age of 4.0 to 4.7 b.y. are from meteorites.The angle of dip for subduction zones are recognized by variations of depth for earthquakes.During a magnetic reversal, the Earth will turn upside down.Most of the Earth's seafloor has been recycled back into the mantle.Primary waves cause the first shaking in an earthquake.2The greater the distance to an earthquake epicenter, the longer the time period between primary and secondary wavesThe fluid motion of the asthenosphere is the cause of the Earth's magnetic field.Basalt magma is a more fluid liquid than that of andesite because it contains less silica and is at ahigher temperature.Ocean crust is primarily comprised of basalt and related igneous rocks.The fluid motion of the asthenosphere is due to partial melt where erupted at the surface is basaltic in composition. The most common rock type erupted above subduction zones is basalt.Pahoehoe is a Hawaiian term applied to blocky basalt flows.The port town of St. Pierre, on the Caribbean Island of Martinique, was destroyed by a nuee ardente.Magmas rise from their source region because they are laden with H2O and other dissolved gases. The greater the distance to an earthquake epicenter, the longer the time period between arrival of primary and secondary waves.Ocean crust melts during subduction forming andesite magma, the dominant volcanic rock of island arcs.Andesitic and rhyolitic eruptions tend to be explosive because of their gas content and high viscosity.Andesite magma is a