Posts treating: "crust"
Friday, 10 June 2016
Mountain Beltway [2016-06-10 14:14:29]
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(733 visits) Mesozoic,Paleozoic; US,
There are some structural goodies here at the confluence of the Rapid River and the Salmon River in west-central Idaho. I visited these outcrops three weeks ago on a field trip after the Rocky Mountain section meeting of GSA. The rocks are the Lightning Creek Schist, a schist that’s part of the Wallowa Terrane, an accreted chunk of crust that docked with western North America during the Mesozoic. Here is
A ten km contour interval? Well yes, if you are mapping the thickness of the earth's crust!
This map brings out beautifully the distribution of the two distinct types of crust on earth. Crust making up the continents is granitic to andesitic in composition, buoyant and is old. Crust making up the ocean basins is mafic in composition, gravitationally unstable (it is heavier and it subducts)
A collapse in the crust of this lava flow reveals a searing hot heart-shaped skylight, a Valentine straight from Mother Earth. Top image: A skylight in the West Kamokuna lava flow with geoscientist for scale. Credit: Laszlo Kestay/USGS Lava in … Continue reading
Northern Iceland is a geothermally active land where heat from deep below the crust melts snow and wreaths the land in steam. Now, new research shows that the tumultuous groundwater beneath northern Iceland’s mist may hold the key to predicting future earthquakes in the region. In a new study presented at the 2015 American Geophysical Union Fall Meeting, researchers found that concentrations of dissolved minerals in groundwater sharply increased before two major earthquakes in northern [...]
At 12:39 UTC (16-November-2015) a magnitude 3,2 earthquake took place in Bárðarbunga volcano. The depth of this earthquake was only 0,5 km so it was not created by magma movement, rather stress changes in the crust. This earthquake … Continue reading
From BBC.I don't know if the link below will work, but if it does, it's a great video of a meteor in the sky over Bangkok. I've never seen a fireball trail that "bursts" several times as this one does. In the image at the left, the thin tail in the upper right is the remnant of at the first burst at high altitude, the center one is stye second, and the left one is just appearing. The meteor appears to have burned up shortly after the third burst appears. Easier to see on the video than to [...]
GeoLog-The official blog of the European Geosciences Union [2015-10-05 14:00:42]
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(269 visits) US,CN,ES,IT
In this week’s Imaggeo on Monday’s image an almost Martian looking landscape, with ombre coloured soils, gives way to gently rolling hills, covered in luscious woods and vegetation. Were it not for the trees in the distance, you would be forgiven for thinking this image had been captured by a Mars rover. In truth, it is an entirely more earthly landscape: welcome to the slopes of Mt. Etna! Keep on reading as Alicia Mourgán, a researcher at the University of València, gives an overview of [...]
Scenary of the Wind River area illustrating that thesurface is covered with sedimentary rocks andsupporting the observation that there is noactive volcanism within about 200 km. From the BBCarticle by Matt Walker cited in the text.Today the BBC has a nice article by Matt Walker pointing out an article by T.J. Craig and R. Heyburn in Earth and Planetary Science Letters (425, pp. 12-23, 2015) on a very deep earthquake in the Wind River range of Wyoming. The authors point out that while [...]
I hear that the Archean Earth Spewed lava and was hot, (While much later, “Snowball Earth,” Apparently was not), Some have said that life sprung out of Spreading-ridge-type stew, Photosynthesis seems likely Based on carbon records, too. Crust was forming, oceans warming, Stromatolites came later, (We have to wait a long, long time for T-Rexes,
Many people love jewelry and other items made of gold. They have
inconspicuous microbes to thank for this: Three billion years ago they
held the noble metal in the Earth’s crust. This is the opinion at least
of an expert from the University of Würzburg.
All the Earth’s gold deposits should actually be in the Earth’s core
– buried deep out of mankind’s reach. After all, this
We're headed on a blog adventure through the most dangerous kind of plate boundary in the world. To make things clear, the boundary we are exploring is not currently the most dangerous in the world, although it is certainly very hazardous. As described in my introduction yesterday, most subduction zones are not easy to explore. Most parts lie underwater or deep in the crust. We are
Since the dawn of mankind, I imagine we’ve gazed
In wonder and awe at the sky’s starry crown;
More recently, we have been deeply amazed
By the long-obscured, staggering view looking down
To the depths of the sea, through crust, and
Earthquakes? Volcanoes? Not this time, anyway...
The seismometer on our campus was going crazy today. Usually such high levels of seismic activity are cause for great concern, due to the rapid movement of magma in the crust, or an impending "big one". But there was no such concern today. The seismic action was due to kids running back and forth down the hallways of our Science
Scientists have used satellites to more accurately measure the slow creep of land along the Calaveras and Hayward faults east of the San Francisco Bay, a finding that helped the researchers estimate the magnitude of future earthquakes. Both the Calaveras and Hayward faults are part of the San Andreas system, which sits at the boundary of two massive slabs of the Earth’s crust called the North American and Pacific plates. The plates slide slowly past one another, sometimes getting stuck and [...]
From USGS web siteA moderate 4.7 magnitude earthquake with an epicenter in Oak Creek Canyon woke me up here in Flagstaff just a few minutes before 11 PM last night. Woken from a moderate sleep, at first I knew it was an earthquake - but then passed it off as a dream and went back to sleep. It seemed to have a jolt followed by about 3 seconds of shaking that gradually diminished.The news coverage has been good this morning. The earthquake summary can be found here on the USGS web [...]
I need some help from you! One of the chapters in my book, Geology Underfoot in Western Washington is about the beautiful Golden Horn granite at Washington Pass. The chapter describes how granitic magma rises through the crust. The tentative title was ‘How Does Granite Rise in the Crust”? My editor at Mountain Press, James
A nice quake swarm is occurring just South of Lassen Volcanic Center in California, US. The largest quake so far in the series has been a 3.9, and at this time the swarm is ongoing. So far around 35 quakes have occurred in the area over magnitude 1. It is unclear at this time whether the quakes are tectonic or volcanic in nature, however the fact that most are quite shallow could indicate this is merely a tectonic or hydrothermal event. Time will tell.Quake swarm south of Lassen. Screenshot [...]
The earth is vast and its surface seems huge. However, the earth’s crust only makes up 1% of the earth’s mass — subsequent layers (the mantle and the core) make up the other 99%. So, why do we care about the earth’s crust … Continue reading
smithsonianmag.com Most of the world’s volcanoes are located deep beneath the sea surface along the mid-ocean ridges where the Earth’s crust spread and creates new ocean floor. Volcanoes on land often occur in subduction zones, where one tectonic plate is diving beneath another, or hotspots created by mantle plumes deep within the planet. READ
The Kansas Geological Survey has published: Induced Seismicity: The Potential for Triggered Earthquakes in Kansas. “Earthquake activity in the Earth’s crust is known as seismicity. When linked to human activities, it is commonly referred to as “induced seismicity.” Industries that have been associated with induced seismicity include oil and gas production, mining, geothermal energy production,