on April 15, 2022
What is the structure of the earth’s crust?
GeologyThis is the outside layer of the earth and is made of solid rock, mostly basalt and granite. There are two types of crust; oceanic and continental. Oceanic crust is denser and thinner and mainly composed of basalt. Continental crust is less dense, thicker, and mainly composed of granite. What is the 3 structure of
on April 15, 2022
Which Hawaiian island has volcanoes?
GeologyHawaii has five main volcanoes that are considered active. Four of these active volcanoes are located on Big Island. They include Kilauea, Mauna Loa, Mauna Kea, and Hualalai. The other is located on Maui and it is Mount Haleakala. Which Hawaiian island has the best volcanoes? the Big Island While all Hawaiian Islands have a
on April 15, 2022
How many earthquakes has Alaska had in 2022?
Geology50,28950,289 reported earthquakes, 2019 finished as a runner up to the record-breaking 2018 (figure 1). How many earthquakes does Alaska have each year? With more than 20,000 earthquakes reported annually, Alaska is by far the most seismically active state. Complex, powerful motions of tectonic plates and crustal blocks generate earthquakes throughout Alaska, including many in
on April 15, 2022
What freeway collapsed the Northridge earthquake?
GeologyA bulldozer tears down a section of the Santa Monica Freeway that collapsed during the Northridge earthquake, on Jan 19. Vehicles are left crushed under the Northridge Meadows apartment complex on Jan. 17. How many freeway bridges collapsed during the Northridge earthquake? Seven years later, the San Fernando earthquake damaged more than 60 bridges on
on April 15, 2022
What is a tufa rock?
GeologyTufa is a highly porous, sedimentary rock (limestone) composed of calcium carbonate, CaCO3. It is formed by biological and chemical precipitation of Calcite or aragonite from cold, supersaturated surface or ground waters. What is tufa rock what is it used for? Tufa is light and was used chiefly from Saxon times to the 14th century.
on April 15, 2022
Was there an earthquake in PA yesterday?
GeologyThere were no significant confirmed earthquakes in or near Pennsylvania in the past 24 hours. Was there any earthquake yesterday? “Earthquake of Magnitude:4.3, Occurred on 29-09-2021, 09:04:10 IST, Lat: 33.29 & Long: 89.07, Depth: 10 Km, Location: 623km N of Lachung, Sikkim, India,” said National Center for Seismology said in a tweet. Was there an
on April 15, 2022
How was Siccar point formed?
GeologyIt is no wonder that Siccar Point is a Scottish National Heritage site. The vertical sediments at Siccar Point are Silurian greywacke, a gray sedimentary rock formed approximately 425 million years ago when colliding plates created immense pressure that converted the sediment to rock. How did the unconformity at Siccar Point form? At Siccar Point,
on April 15, 2022
What are four different landforms created by Lava?
GeologyKey Concept:Volcanic eruptions create landforms made of lava, ash, and other materials. These landforms include shield volcanoes, cinder cone volcanoes, composite volcanoes, and lava plateaus. A shield volcano is a gently sloping mountain. It forms when a volcano erupts quietly. What is the most common landform created by lava? The most obvious landforms created by
on April 15, 2022
When did the Ice Age Floods affect the Columbia River Gorge?
GeologyBetween 18,000 and 14,000 years ago, raging flood waters and icebergs in 40 to 120 Ice Age Floods tore away at the exterior cone, leaving Beacon Rock as a basalt monolith sticking out of the north bank of the Columbia River. When did the Ice Age Floods happen? 18,000 to 12,000 years ago During the
on April 15, 2022
When did the San Andreas Fault form?
GeologyThe San Andreas Fault was born about 30 million years ago in California, when the Pacific Plate and the North America plate first met. Before then, another oceanic plate, the Farallon plate, was disappearing beneath North America at a subduction zone, another type of plate boundary. When did the San Andreas fault begin to form?