Small eruption at Maly Semyachik volcano, the first since 1952, Russia

maly-semyachik-volcano-eruption-july-2017

According to data provided by the Tokyo VAAC, a small eruption took place at Russia's Maly Semychik volcano at 06:40 UTC on July 7, 2017. The last known eruption of this volcano took place in 1952, 65 years ago. The Aviation Color Code remains Green.

The reported ash cloud reached an altitude of just 2.1 km (7 000 feet) above sea level, 600 m (1 970 feet) above the summit. The plume drifted to the southwest at 18 km/h (11 mph).

This was a small eruption but could be a precursor to a larger one. Maly Semychik's hazards are explosive eruptions which produce ash plumes, ashfall, pyroclastic flows and lahars.

KVERT has not issued a Volcano Observatory Notice for Aviation (VONA), and the Aviation Color Code remains Green.

The Global Volcanism Program has no Weekly Reports available for this volcano.

The last known eruption of Maly Semychik took place at its Troitsky Crater in December 1952. It had Volcanic Explosivity Index (VEI) of 2.

This volcano is located 20 km (12.4 miles) west from the coast of the Kronotsky Bay, 15 km (9.32 miles) northeast from Karymsky volcano, and 140 km (87 miles) northeast from Petropavlovsk-Kamchatsky.

Its structure is a 3 km (1.8 miles) long volcanic ridge build up with 3 close stratovolcanoes: Paleo-Semyachik, Meso-Semyachik, and Ceno-Semyachic. Ceno-Semyachic includes Troitsky crater with a thermal Lake.

Geological summary

Maly Semyachik is a compound stratovolcano located in a 10-km-wide (6.2 miles) caldera within the 15 x 20 km (9.3 x 12.4 miles) mid-Pleistocene Stena-Soboliny caldera. Following construction during the late Pleistocene of the Paleo-Semiachik volcano beginning about 20000 years before present (BP), activity migrated to the SW, forming Meso-Semiachik (about 11000 – 9000 BP) and Ceno-Semiachik (about 8000 BP to the present).

An initial stage lasting about 3500 years was dominantly explosive, constructing the present cone. A second stage beginning about 4400 years ago was marked by alternating constructive and destructive processes during which the volcano was destroyed by major explosions and then reconstructed. A crater lake fills the historically active Troitsky Crater, which formed during a large explosive eruption about 400 years ago.

Featured image: The broad Maly Semiachik massif, seen here from the SW on the flanks of Karymsky volcano, is composed of three overlapping stratovolcanoes constructed along a NW-SE line. The volcano was built within two overlapping Pleistocene calderas.  The rim of the larger 12-km-wide (7.4 miles) Steena caldera is visible on the far right horizon, but elsewhere its rim is largely buried. The late-Pleistocene to Holocene post-caldera massif almost completely obscures the rim of the inner 7-km-wide (4.3 miles) Maly Semiachik caldera. Credit: USGS / Dan Miller, 1990 

If you value what we do here, create your ad-free account and support our journalism.

Share:


Your support makes a difference

Dear valued reader,

We hope that our website has been a valuable resource for you.

The reality is that it takes a lot of time, effort, and resources to maintain and grow this website. We rely on the support of readers like you to keep providing high-quality content.

If you have found our website to be helpful, please consider making a contribution to help us continue to bring you the information you need. Your support means the world to us and helps us to keep doing what we love.

Support us by choosing your support level – Silver, Gold or Platinum. Other support options include Patreon pledges and sending us a one-off payment using PayPal.

Thank you for your consideration. Your support is greatly appreciated.

Sincerely,
Teo Blašković

$5 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$50 /year

$10 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$100 /year

$25 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$200 /year

You can also support us on Patreon

support us on patreon

or by sending us a one-off payment using PayPal:


Commenting rules and guidelines

We value the thoughts and opinions of our readers and welcome healthy discussions on our website. In order to maintain a respectful and positive community, we ask that all commenters follow these rules:

  • Treat others with kindness and respect.
  • Stay on topic and contribute to the conversation in a meaningful way.
  • Do not use abusive or hateful language.
  • Do not spam or promote unrelated products or services.
  • Do not post any personal information or content that is illegal, obscene, or otherwise inappropriate.

We reserve the right to remove any comments that violate these rules. By commenting on our website, you agree to abide by these guidelines. Thank you for helping to create a positive and welcoming environment for all.

Leave a reply

Your email address will not be published. Required fields are marked *