Posts tagged geology
Posts tagged geology
Lena Stone Pillars Russia
One of the most beautiful natural wonders of Russia, Lena’s Stone Forest is also one of the most difficult to reach,It lies in a part of Siberia not yet touched by civilization.
Known also as Lena’s Stone Pillars, this incredible rock formation is not only beautiful to look at, it’s also holds important information on the formation of the organic world. Fossils from various organisms dating back to the Cambrian era could supply invaluable insight on life evolved on planet Earth.The amazing stone structures towers over 150 meters in height and extends along the river Lena for about 80km.
ʻĪao Needle, April 2013
The ʻĪao Needle rises 1,200 ft (370 m) from the floor of the ‘Iao Valley, Maui. The valley formed as water eroded the caldera of the old West Maui volcano. An erosional remnant, the ‘Iao Neele is at the end of a ridge comprised of a denser dike stone. The softer rock around the dike stone was eroded by streams and waterfalls.
`Iao is so sacred that the remains of the highest chiefs were entrusted to secret hiding places in the valley. Kaka`e, ruler of Maui in the late 1400’s to 1500’s, is believed to have designated this valley as an ali`i burial area.
Reference (including a picture in sunshine!)
SUBMISSION: Angular folding in platy limestones, Agios Pavlos, Crete.
Grinnell Glacier is in the heart of Glacier National Park in the U.S. state of Montana. The glacier is named for George Bird Grinnell, an early American conservationist and explorer, who was also a strong advocate of ensuring the creation of Glacier National Park. The glacier is in the Lewis Range and rests on the north flank of Mount Gould at an altitude averaging 7,000 feet (2,100 m), in the Many Glacier region of the park…
(read more: http://en.wikipedia.org/wiki/Grinnell_Glacier)
(photo: Mountain_Walrus | Wiki)
The quoted part is all factual, but not really a good explanation of this particular quake:
The strongest earthquake to hit Iran in more than 50 years was a subduction-zone quake — the same tectonic setting underlying deadly temblors in Japan, Chile and Indonesia.
The magnitude-7.8 Khash earthquake struck 51 miles (82 kilometers) beneath the Earth’s surface, where the Arabian Plate dives under the massive Eurasian Plate, the U.S. Geological Survey (USGS) reported. The quake hit today (April 16) at 3:14 p.m. local time (6:44 a.m. EDT). Shaking was felt from New Delhi to Dubai, and dozens of people have been reported killed by collapsed structures, according to news reports. The USGS said that there will be more than a 47 percent chance of more than 1,000 fatalities.
Known as the Makran subduction zone, the plate boundary has produced some of the Middle East’s biggest and deadliest earthquakes. For example, in November 1945, a magnitude-8.0 earthquake in Pakistan triggered a tsunami within the Gulf of Oman and the Arabian Sea, killing more than 4,000 people….
A smaller earthquake hit Iran on April 9. The magnitude-6.3 Bushehr earthquake, which hit in the southern Zagros Mountains, was unrelated to today’s temblor, the USGS said. That quake was a thrust-fault earthquake, meaning the ground on one side of the fault moved vertically up and over the other side, shortening the distance between the two sides. The epicenter was 55 miles (89 km) southeast of Bushehr, the city where Iran’s only nuclear power station is located.
The USGS moment tensor solutions indicate that this earthquake had a NORMAL sense of motion (the opposite of thrust), leading them to believe it is related to flexture of the down-going slab. That means it is did not occur on the subduction boundary and is NOT comparable to the giant earthquakes experienced in Japan, Chile and Indonesia in recent years. Those others occurred on the subduction interface itself, a type of fault frequently referred to as a “megathrust” fault. A M7.8 on a megathrust would be locally significant, but not large by subduction zone standards. A M7.8 on a normal fault is uncommonly large and much more interesting.
Instead of saying “It’s just another subduction zone earthquake”, we should be saying “This earthquake shows us how complicated subduction zones can be and that we need to be prepared for more than one type of event in these hazardous areas.”
Petoskey Stone is fossilized coral that lived in warm, shallow seas that covered Michigan during Devonian Period, around 350 million years ago.
(Photo credit: J Clark)
A better picture of Kiluea Iki.
Kilauea Iki is a pit crater adjacent to the main Kilauea caldera.
This is me, about 100 meters underground in a dolostone mine, about to hit a 15 m x 15 m pillar of rock with a hammer. The little blue thing to the right is one of 24 geophones coupled into the sides of the pillar. They detect and record the seismic waves created by my hammer blow. I use these seismic waves to create an image of the interior of the pillar. Pretty cool, right?
This looks pretty awesome, where was the mine?
Timescales from recharge to discharge
USGS (click through for Basic Groundwater Hydrology, Heath, 1987).
Wonder where on Earth to collect space rocks? Stay at home. The map above shows every meteorite strike known to fall on earthly terrain. And from the looks of it, the United States is prime collecting grounds.
Grab your shovels! Time to find us some space rocks! Read more
The title of this post is misleading! The data is good, but the presentation implies that “crash landings” have only occurred where we have mapped them.
In reality, the number of meteorites found in any particular place is more related to the environment of that place than to the frequency of meteorite impacts in that place. The western US has low rainfall and few trees, making it a good place for preservation of random chunks on the surface. In contrast, the Amazon and Congo river basins are full of trees, making rock hunting difficult, and have high rainfall/erosion/resedimentation rates, meaning chunks on the surface don’t stay there very long.
If you want to find meteorites, this map is useful. If you want to know about where meteors strike, this map is very very incomplete.