Image: Volcanic smog and sunglint in the Vanuatu Archipelago

Jan 23, 2014
Credit: NASA/Jeff Schmaltz/MODIS Rapid Response Team

The Vanuatu Archipelago is a collection of volcanic islands about 1,800 kilometers (1,100 miles) northeast of Australia. Two of the islands, Gaua and Ambrym, frequently vent sulfurous gases.

On Jan. 7, 2014 NASA's Aqua satellite passed over Vanuatu, allowing the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard to capture this true-color image. A broad plume of volcanic vog and ash rises from Ambrym and spreads across the South Pacific. Vog is a combination of "volcanic" and "smog", and is formed when gases from a volcano react with sunlight, oxygen and moisture.

The vog appears as a light blue-gray plume which arcs from the volcanic island both to the northwest and to the northeast. In the northeast, the vog crosses a mirror-like swath of silver-gray which runs from north to south. That swath is not volcanic in origin, but is an artifact called "sunglint" – the reflection of the sun off the ocean in a satellite image.

Explore further: Source of Galapagos eruptions is not where models place it

add to favorites email to friend print save as pdf

Related Stories

Ash plume from Shiveluch volcano

Oct 12, 2012

When NASA's Terra satellite passed over Russia's Kamchatka Peninsula at noon local time (00:00 Universal Time) on October 6, 2012, Shilveluch Volcano was quiet (top image). By the time NASA's Aqua satellite pa ...

NASA sends unmanned aircraft to study volcanic plume

Apr 02, 2013

(Phys.org) —Studying volcanos can be hazardous work, both for researchers and aircraft. To penetrate such dangerous airspace, unmanned aerial vehicles (UAVs), especially those with electric engines that ...

Recommended for you

Strong quake hits east Indonesia; no tsunami threat

21 hours ago

A strong earthquake struck off the coast of eastern Indonesia on Sunday evening, but there were no immediate reports of injuries or damage, and authorities said there was no threat of a tsunami.

Scientists make strides in tsunami warning since 2004

Dec 19, 2014

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

Dec 19, 2014

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.