How does heat flow vary over Earth’s surface?
GeologySo at the top of the asthenosphere, the hot rock flows along the bottom of the lithosphere, transferring its heat to the cold rocks by conduction. The heat then flows through to the surface, again by conduction. What does heat flow depend on? The rate of heat transfer depends on the material through which heat
How does radioactive decay determine the age of rocks?
GeologyThe age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer. How is radioactive decay used to date
Why is a divergent boundary also called a constructive boundary?
GeologyAt a divergent plate boundary – also known as a constructive plate boundary, the plates move apart from one another. When this happens the magma from the mantle rises up to make (or construct) new crust. The movement of the plates over the mantle can cause earthquakes. Rising magma can also create shield volcanoes .
How does water shape the earth?
GeologyWater moving across the earth in streams and rivers pushes along soil and breaks down pieces of rock in a process called erosion. The moving water carries away rock and soil from some areas and deposits them in other areas, creating new landforms or changing the course of a stream or river. How does water
How much damage did the Anchorage earthquake cause?
GeologyThe four minute duration of shaking triggered many landslides and avalanches. Major structural damage occurred in many of the major cities in Alaska. The damage totalled 300-400 million dollars (1964 dollars). The number of deaths from the earthquake totalled 131; 115 in Alaska and 16 in Oregon and California. How strong was the earthquake in
What was the worst earthquake in US history?
GeologyThe Largest Earthquakes in the United States RANK MAGNITUDE DATE 1. 9.2 March 28, 1964 2. 8.8 March 9, 1957 3. 8.7 Feb. 4, 1965 4. 8.3 Nov. 10, 1938 What are the 5 largest earthquakes ever recorded in USA? 5 of the most devastating earthquakes in US history Charleston, South Carolina 1886. Northridge, California
What period did Ammonite live in?
GeologyJurassicJurassic and Cretaceous. Together, these represent a time interval of about 140 million years. The Jurassic Period began about 201 million years ago and the Cretaceous Period ended about 66 million years ago. Did ammonites live in the Mesozoic Era? Evolution and extinction As ammonites evolved throughout the Mesozoic era, between 252 and 66 million
When did the Columbia River basalts form?
Geologyabout 17 million years agoabout 17 million years ago. How old is the Columbia River Basalt? 16.7 million years old The Columbia River Basalts (CRBs) are a series of broad lava flows known as flood basalts . The CRBs currently cover large portions of southeast Washington, northeast Oregon and western Idaho. At 16.7 million years
What was the cause of the Great Hanshin Earthquake?
GeologyThe great Hanshin earthquake was caused by plate motion under Hanshin area. The inland shallow earthquake type decides its severe damage to cities such as Kobe and Osaka, by both shocking waves and soil liquification. What plates caused the Great Hanshin Earthquake? The Kobe quake was a result of an east-west strike-slip fault where the
What are the characteristics of a clastic sedimentary rock?
GeologyClastic sedimentary rocks are named according to the characteristics of clasts (rock and mineral fragments) that comprise them. These characteristics include grain size, shape, and sorting. How do you identify a clastic sedimentary rock? Clastic sedimentary rocks are subdivided on the basis of grain size. Secondary characteristics used to further distinguish clastic rocks are sorting,