on April 15, 2022
What are typical rates of seafloor spreading?
GeologyThese age data also allow the rate of seafloor spreading to be determined, and they show that rates vary from about 0.1 cm (0.04 inch) per year to 17 cm (6.7 inches) per year. Does seafloor spreading occur at the same rate? Seafloor spreading is mainly the result of convection currents dragging the ocean plate
on April 15, 2022
What exactly is magma?
GeologyWhat is magma What is it made of? Magma is a molten and semi-molten rock mixture found under the surface of the Earth. This mixture is usually made up of four parts: a hot liquid base, called the melt; minerals crystallized by the melt; solid rocks incorporated into the melt from the surrounding confines; and
on April 15, 2022
Where can you find limonite?
GeologyLimonite is common and occurs within concretions and cavity fillings in sedimentary rocks and as coatings on the rocks, especially sandstone. It also occurs as iron rust and accumulates around rootlets in soils. Where can limonite be found? Limonite is a very common mineral and can be found throughout the world, with major deposits located
on April 15, 2022
What type of rock created the first continents?
Geologyigneous protolithpartial melting of an older igneous protolith; however, both the composition of the protolith and its tectonic affinity are controversial. Field and analytical studies suggest that the early continents were formed by partial melting of oceanic crust in primitive subduction zones. What type of rock made the first continents? basalts The Earth’s oldest continental
on April 15, 2022
What type of earthquake generates a tsunami?
GeologyMost tsunamis are generated by earthquakes with magnitudes over 7.0 that occur under or very near the ocean and less than 100 kilometers (62 miles) below Earth’s surface (earthquakes deeper than this are unlikely to displace the ocean floor). What type of earthquake produces tsunamis? The earthquake must be a shallow marine event that displaces
on April 15, 2022
When was the Washington monument damaged by an earthquake?
GeologyAugust 23, 2011August 23, 2011, a 5.8 magnitude earthquake, occurred 84 miles southwest of Washington, D.C., damaging the Washington Monument. The National Park Service has temporarily closed the Monument and is assessing the damage to it. When did the Washington Monument reopen after the earthquake? Sept. 19 Washington Monument, closed for five of the past
on April 15, 2022
What causes convection currents in the atmosphere?
GeologyConvection currents are created in the Earth’s atmosphere as the sun heats the gases, causing them to rise. Theses gases cool as they rise high into the atmosphere and travel back down towards the ground to get heated again. What are the main causes of convection currents in the asthenosphere? Convection occurs in the asthenosphere
on April 15, 2022
Is Dante’s Peak based on Mount St Helens?
GeologyThe volcanic inspiration for “Dante’s Peak” was the 1980 eruption of Mount St. Helens, which was used as a filming location for some scenes in the movie. “Dante’s Peak” is also strikingly similar to the 1981 movie “St. Helens,” which portrays a slightly dramatized story about the real event. Where is Dante’s Peak based? Dante’s
on April 15, 2022
What are the three forces that cause plate motion?
GeologyConvection occurs in the mantle underneath Earth’s tectonic plates. Three forces act on the plates to make them move: basal drag from convection currents, ridge push at mid-ocean ridges, and slab pull from subducting plates. Convection currents in the mantle produce a force that causes motion called basal drag. What are three ways forces of
on April 15, 2022
Is sand a product of weathering?
GeologyAfter a series of weathering cycles, sand-sized material will be produced and the grains continue to reflect the parent rocks. What are products of weathering? As weathering proceeds, they are likely to be broken into small pieces and converted into clay minerals and dissolved ions. Ultimately this means that quartz, clay minerals, iron oxides, aluminum