In the month of October, the Mississippi River has seen record low levels from Illinois to Louisiana. In Baton Rouge, the level is revealing a more than 100-year-old sunken ferry and the underbelly of the USS Kidd.
Environment
Oct 28, 2022
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51
The sightlines at Wrigley Field, the panorama from Navy Pier, the vantage points at the Adler Planetarium observatory—all structures built more than 100 years ago—are at least 4 inches lower now.
Environment
Mar 4, 2019
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89
With cybersecurity one of the nation's top security concerns and billions of people affected by breaches last year, government and businesses are spending more time and money defending against it. Researchers at the U.S. ...
Security
Apr 17, 2019
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88
It’s the last play of the big game, only seconds left and the quarterback throws toward the end zone and … blackness.
Engineering
Nov 19, 2010
1
0
A Griffith-led study has assessed whether basic human water needs can be met without exceeding safe and just Earth system boundaries (ESBs) for surface and groundwater (blue water), defined to protect people and planet.
Earth Sciences
Nov 29, 2023
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100
Sony said Wednesday intruders staged a massive attempt to access user accounts on its PlayStation Network and other online entertainment services in the second major attack on its flagship gaming site this year.
Internet
Oct 12, 2011
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0
Morningstar Inc. says it discovered an illegal intrusion into its systems that may have compromised some of its clients' personal information, including email addresses, passwords, and credit card numbers.
Internet
Jul 6, 2013
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0
(AP) -- In a cautionary tale for users of social-networking sites, a California man has admitted using personal information he gleaned from Facebook to hack into women's e-mail accounts, then send nude pictures of them to ...
Internet
Jan 15, 2011
13
0
Supporters of the large-scale Mississippi River sediment diversions currently being planned by the Louisiana Coastal Protection and Restoration Authority got a boost to their case recently when Louisiana State University ...
Environment
Dec 1, 2022
1
54
Researchers at The Ohio State University have created high-resolution maps of points around the globe where groundwater meets the oceans—the first such analysis of its kind, giving important data points to communities and ...
Earth Sciences
Jun 3, 2019
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163
An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly cools into a solid, the different parts of the magma crystallize into minerals. Many mountain ranges, such as the Sierra Nevada in California, are formed mostly by intrusive rock, large granite (or related rock) formations.
Intrusions are one of the two ways igneous rock can form; the other is extrusive, that is, a volcano eruption or similar event. Technically speaking, an intrusion is any formation of intrusive igneous rock; rock formed from magma that cools and solidifies within the crust of a planet. In contrast, an extrusion consists of extrusive rock; rock formed above the surface of the crust.
Intrusions vary widely, from mountain range sized batholiths to thin vein-like fracture fillings of aplite or pegmatite. When exposed by erosion, these cores called batholiths may occupy huge areas of Earth's surface. Large bodies of magma that solidify underground before they reach the surface of the crust are called plutons.
Coarse grained intrusive igneous rocks that form at depth within the earth are called abyssal while those that form near the surface are called hypabyssal. Intrusive structures are often classified according to whether or not they are parallel to the bedding planes or foliation of the country rock: if the intrusion is parallel the body is concordant, otherwise it is discordant.
A well-known example of an intrusion is Devil's Tower.
This text uses material from Wikipedia, licensed under CC BY-SA
