Thursday, February 24, 2005

Two small outbursts and a large scar

The Volcanocam images from last night captured two small outbursts of activity, one at 21:53 and another slightly larger flash at 03:43 (local time).

Meanwhile, the USGS/CVO have posted images of a scar on the west side of the lava dome roughly 100 m long and 50 m high, which is believed to be the source of the large outburst of activity on Tuesday night. One of the images is shown below.

Credit: USGS Photograph taken on February 22, 2005, by Steve Schilling

Wednesday, February 23, 2005

Multiple outbursts on Mount St Helens last night

The level of activity on Mount St Helens increased this morning, with two separate outbursts occurring at 02:13 and 04:08 (local time).

The second event resulted in at least two distinct glows following the outburst, something we haven't seen on the mountain for months. The two glows appeared to be on opposite sides of the lavadome, which may mean further fracturing and landslides from the ridge of the dome.

New movies of the events have been posted and a picture of the dual glows visible in the crater is shown below.

Tuesday, February 22, 2005

Mount St Helens lights up the night.

There was a major outburst of activity on Mount St Helens at 03:03am this morning. This was one of the largest and brightest events that we have so far seen on the nightly Volcanocam images.

Saturday, February 19, 2005

Several outbursts of activity on Mount St Helens

There were several bright flashes clearly visible on the processed images from last night. It is clear that there were several landslides exposing fresh hot lava to the surface on both sides of the growing dome.

As reported yesterday, the lavadome has developed a number of large fractures along its length, which may lead to increased landslides and night time activity. A recent infra-red image from the USGS/CVO shows the fractures quite clearly.

Friday, February 18, 2005

Mount St Helens - update and promise of nighttime activity?

Last night the glow from the lavadome was almost non-existent, although it was visible after considerable image enhancement.

The USGS/CVO are reporting that the "[r]esults of Wednesday’s thermal-imaging flight suggest that a longitudinal crack is developing along the top of the new lava dome. Similar to what happened in mid-December, the long smooth whaleback-shaped dome may be starting to crack apart. During such a process, the probability of rock avalanches increases and with that an increased chance of more ash clouds rising above the crater rim than we’ve witnessed in recent weeks."

This will almost certainly mean that further outbursts of activity are likely in the coming days/weeks and if they occur at night, bright displays during the night. Stay tuned...

Thursday, February 17, 2005

Enceladus - amazing detail

The NASA and the Cassini Imaging Team (CICLOPS) have released the first raw images from the Cassini probes close flyby of Saturn's moon Enceladus. The surface is litterally out of this world. Cratered, fractured, cracked, and just plain weird - pick a geologic feature and you can pretty much see it somewhere on these images!

The image below was produced from two of the raw images stitched together...

Mount St Helens glowing dimly at best

The mountain was clear last night and there were no major outbursts of activity. The incandescent glow from the lavadome was extremely faint, almost to the point of barely being discernible from the background noise in the images. A movie of last nights images which have been enhanced to show the glow activity is available.

The USGS/CVO have released more close up images of the crater, including an interesting sequence of images showing the incredible growth of the lavadome over the last few months.

Wednesday, February 16, 2005

First impact crater positively id'd on Titan?

The images of Titan from Cassini's latest flyby are starting to be relayed back to Earth and the first results of the radar mapping of the surface have just been posted by NASA. The radar mosaic reveals a large (440km diameter) annular structure on Titan's surface, possibly a large impact crater. If confirmed, this would be the first impact structure positively identified on the moon's surface.

Credit: NASA/JPL

Tuesday, February 15, 2005

Mount St Helens glows again...

The incandescent glow from the crater was visible for most of the night. But there were no major outbursts of acivity recorded. The movie of last nights display is available here.

Monday, February 14, 2005

Cassini approaches Titan

In a little over twelve hours the Cassini space probe will make its next close approach to Saturn's moon Titan. The last closest approach was two months ago when Cassini released the Huygens probe and placed it on course to land on Titan's surface.

Below are two overlayed images of Titan. The first taken by Cassini in Dec 2004 and the second taken on 12 Feb 2005. While the alignment of the two images isn't exact, its interesting to see that most of the surface features appear to have changed little in the last two months. At least at this scale...

Saturday, February 12, 2005

Two minor outbursts on Mount St Helens last night

The glow was fairly feeble for most of last night, apart from two small outbursts of activity at 20:18 and 2138 local time (PST). The image below was created by stacking several hours of images together. The two flashes are clearly seen at different locations on the lavadome. There's also a movie of last night's activity available.

Thursday, February 10, 2005

Another outburst of activity on Mount St Helens

The Volcanocam images from last night recorded another bright flash from Mount St Helens at 01:38 local time. Below is an image of the flash, superimposed on a daytime photo of the mountain for reference. A movie of the event is also available.

The USGS/CVO have posted new images (taken on 8 February) showing the growth and fractures of the new lavadome.

Wednesday, February 09, 2005

A brief flash from Mount St Helens

There was a small (& brief) outburst of activity visible on last nights images from Mount St Helens at 03:38 local time. otherwise the glow was faintly visible for the entire night.

Tuesday, February 08, 2005

A distant glow on Mount St Helens

The Volcanocam images from last night showed a very faint glow that lasted throughout the entire night. There were no bright flashes or other exciting events... A new movie of last nights display is available.

Monday, February 07, 2005

More activity at Mount St Helens

Last night the clouds cleared allowing the Volcanocam to record another bright flash from Mount St Helens at 01:13 local time. These bright flashes of light are believed to be caused by the lavadome fracturing and exposing fresh hot lava to the surface.

Below is an image of the flash, superimposed on a daytime photo of the mountain for reference, in order to locate the region where the flash eminated. The second image shows a seismic signal occuring just prior to the Volcanocam image of the flash. I have also posted a movie of the event here.

Credits: Original image, US Forest Service Volcanocam

Credit: The Pacific Northwest Seismograph Network

Friday, February 04, 2005

Hubble spies changing light echo

The Hubble Telescope has imaged dramatic changes in the illumination of dust surrounding the star V838 Monocerotis (V838 Mon) over the last 3 years. The star brightened unexpectedly in 1992 and the burst of light has been illiminating an ever expanding region of the dust surrounding the star ever since. This effect is known as a light echo.

The animation below was produced by aligning the different images taken by Hubble since 1992.

Image Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

Another flash on the mountain last night

The glow illuminating the crater of Mount St Helens was faintly visible for most of the night. At 03:38 local time another bright flash eminated from the crater, which was most likely caused by another small rockfall/fracture of the lavadome. A new movie of the event is available...

Thursday, February 03, 2005

Mount St Helens last night

The Volcanocam images from last night revealed a faint glow that lasted for the entire night. It was a little brighter than over the previous nights, most likely because of the small ash/steam event that occurred yesterday afternoon. New movies from last night have been posted!

UPDATE: Another minor ash/steam explosion occurred today beginning at around 12:30pm.

Wednesday, February 02, 2005

Mount St Helen's erupts!

A steam and ash eruption began about 1 hour ago - this is probably the lavadome fracturing and large slabs of material breaking off and falling away. Which would make this event similar to those seen at night causing bright flashes to occur in the crater. To following the event as it unfolds go to the Volcanocam website...

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