The Earth Story

Kilimanjaro

Cosmonaut Oleg Artemyev captured this gorgeous view of the Kilimanjaro volcanic complex sticking its head above a sea of clouds earlier this month. From this vantage point you can see both the central volcanic crater at the summit and the highest point in Africa, on the rim of that crater. The high point just to the edge of the crater is called Uhuru peak and a recent survey assessed it to reach 5891 meters above sea level.

Kilimanjaro is the culmination of 3 volcanic complexes built up over the last 2 million years. Lavas on the slopes of the main peak, partially buried by more recent activity, show that there was a volcano developed here between 2.3 and 1.9 million years ago. That volcano, known as Shira, remains as a ridge on the slope of the largest peak today. 1.9 million years ago, that volcano collapsed to form a caldera, prior to nearly a million years of quiet at this site, and during that time the former peak partially eroded away.

950,000 years ago, volcanism restarted at the site seen off to the left edge of this image, a summit called Mawenzi. This peak was built up out of lava flows between 950,000 and 488,000 years ago. Eruptions at this peak ceased after a major collapse and avalanche event, which triggered lahars that flowed down the slopes.

The main peak of Kilimanjaro is known as Kibo. Activity on it may have started as early as 1 million years ago, but the youngest well-exposed activity is about 463,000 years old. It is likely that both Kibo and Mawenzi were erupting simultaneously as those 463,000 year old rocks are at roughly the same elevation as the summit of Mawenzi – meaning the volcano had to grow to that height by that time. These eruptions have partially buried the remnants of Shira, leaving it only weakly exposed. The main summit grew through a series of explosive, crater and caldera forming eruptions, intrusive lava flows, and dome formations. The flat summit of this peak is thought to have formed in an eruption about 200,000 years ago, associated with an intrusion of igneous rocks, a dome collapse, and lahars that probably involved melting glaciers at the summit.

Smaller cinder cones have formed since this last main volcano-building event, and these dot the landscape around the main mountain.

-JBB

Image credit: https://twitter.com/OlegMKS/status/1028582780358283264

References: http://ceur-ws.org/Vol-1142/paper12.pdf http://bit.ly/2OK9qgQ_ _

Nearly a full night viewed from orbit on the International Space Station - I think starting in South America and winding up in Eastern Europe.

Cosmonaut Sergey Ryazanskiy shared this timelapse video taken as the International Space Station flew over Italy, Sardinia, Sicily, the Mediterranean, and Africa. Really neat overflight of a lightning storm in the latter part.

Klyuchevskaya

Russian Cosmonaut Anton Shkaplerov recently took this photo of Klyuchevskaya Sopka, a basaltic stratovolcano with a steep, symmetrical cone on the Kamchatka Peninsula. The photo shows smoke billowing out of the volcano, which is pretty much the normal state of this active volcano.

Klyuchevskaya is the tallest mountain on the peninsula at 4,750 meters (15,580 feet) above sea level. It’s not the most active volcano there, that’s nearby Karymsky, but it’s still among the most active volcanoes in the world having erupted over 60 times since 1900. The most recent eruption was January 1 through March 24, which took place after only about a year of relative calm.

The Kamchatka Peninsula is bordered by the Sea of Okhotsk to the west, and the Pacific Ocean and Bering Sea to the east. It is also in the Ring of Fire, right where the Pacific Plate is sliding beneath the Okhotsk Plate. As the plate is forced downwards, temperature and pressure melt the rock and turn it into magma, which can then migrate towards the surface and cause volcanic eruptions.

There are over 100 volcanoes on the Kamchatka Peninsula, and 40 of them are active – meaning they may be erupting now or could erupt relatively soon. Additionally there are a number of geysers and hot springs.

- RE

Photo Credit: Cosmonaut Anton Shkaplerov http://bit.ly/1H29LTd

Previous Posts: http://on.fb.me/1RhCCbR http://on.fb.me/1DUVFOK http://on.fb.me/1DUVItY

References: http://bit.ly/1Ik98rk http://1.usa.gov/1mdGx9C http://bit.ly/1QqTZWg http://bit.ly/1ET8BIN

Take that, Isaac Newton

Isaac Newton is one of many scientists throughout history who was fascinated by the way a prism splits light into many colors.

This image of a sunset was shared by cosmonaut Oleg Artemyev from the International Space Station. I can’t help but think that the scientists who did all that work with prisms centuries ago would be truly in awe at this one.

-JBB

Image credit: http://www.artemjew.ru/2014/08/12/sunset-iss/

Up Up and Away! This gorgeous long exposure photo shows the flight path of the spaceflyers' Soyuz TMA-12M rocket. The rocket, headed for the International Space Station, launched from Baikonur Cosmodrome in Kazakhstan on Wednesday, March 26, 2014. On board was NASA astronaut Steven Swanson as well as two Russian cosmonauts: Alexander Skvortsov and Oleg Artemyev. The trio will spend the next 6 months working in space. -Jean Photo courtesy of NASA