Mount St Helens


30th anniversay of Mount St Helens eruption


2011 Updates for the last week (or so...)

11 March - The M8.9 megaquake off the coast of Japan has caused extensive damage and spawned a devestating tsunami. Tsunmai alerts and warnings have been issued across the Pacific ocean. The seismographs at Mount St Helens recorded the events as show on the HSR, SHW and VALT webicorder traces.

31 January - There was a brief burst of low level activity on the 29th, with a number of small tremors, the largest of which were M2.6 and M2.5. Also see the webicorder traces at SHW, HSR, & JUN stations.

12 January - It's been a while since I have made an update. The situation at Mount St Helens has been "uneventful" over the last few months. The webicorders have recorded a few distant events, but nothing that indicates that the mountain is showing any significant signs of life.

12 October - Mount St Helens has continues to display little activity of any significance. The volcano has been very quiet, with only a few micro-quakes over the last few weeks. The Volcanocam images from today show a sunny sky and clear views of the mountain.

10 September - There have been a few small micro-quakes at Mount St Helens over the last couple of weeks, but nothing of any significance. The volcano continues in a passive state with no signs of any re-newed activity. The Volcanocam images continue to show mostly cloudy activity at the moment.

19 August - There was a M2.2 quake at Mount St Helens on Tuesday afternoon at 16:25 PDT, which can clearly be seen on the MSH webicorders. e.g. see HSR, SEP & VALT traces. The other obvious small quake visible on the traces at 12:39 PDT was centred 19km NNW of MSH.

03 August - The last two weeks have shown some small tremors from Mount St Helens, but nothing to indicate any significant level of increase in seismic activity. The Volcanocam images have shown some steam rising from the lavadome over the few couple of days, but this is most likely due to water infiltrating the residual heat in the lavadome, and not any new increase in activity that would be of concern.

18 July - I have been away and unable to access the website for the past few weeks, apologies to all. reviewing the webicorder records for the last months, shows a couple of small quakes at MSH, but no major increase in seismic activity. A number of distant quakes have appeared on the charts, but once agin nothing close to Mount St helens.

26 June - Seismic activity has remained at background levels over the last week, with no events of any particular note. The weather has improved with clear views of Mount St Helens to be seen on the Volcanocam images.

17 June - Reviewing the MSH webicorders this morning shows a quake at 07:23 PDT, much larger than we have seen for some time. e.g. see HSR chart. However, this was not associated with Mount St Helens, but was a M4.2 quake situated 31 km (19 miles) S of White Swan, WA.

15 June - There was a small M1.2 micro-quake at Mount St Helens on Sunday morning at 09:26 PDT, also see HSR webicorder trace. The poor weather conditions continue at MSH, with more clouds, rain (and possibly snow) expected in the next week.

10 June - A small tremor appeared on the MSH webicorders last night at 19:47 PDT, that appears to be located at/near Mount St Helens. e.g. see HSR webicorder trace. Otherwise seismic activity remains low and the inclement weather continues to obscure views from the Volcanocam cameras. Although the forecast looks promising for the weekend.

07 June - Seismic activity at Mount St Helens remains at low/background levels with no events of note over the last week. Summer has been fairly absent from the images from the Volcanocam cameras, with some views of the lower flanks of the mountain today. The weather forecast isn't very summer-like either, with rain and possibly snow predicted in the coming week!

31 May - Since the last update on the 30th anniversary of the 1980 eruption, there has been little to no activity of note at Mount St Helens. Seismic activity has remained at background levels and the view of the crater from the Volcanocam cameras has remained largely obscured by clouds. The weather forecast calls for more rain and clouds through the end of the week.

18 May - It was 30 years ago today that Mount St Helens blew its top in one of the largest volcanic eruptions of recent times. Fortunately, the mountain is much quieter at present. In fact there has been virtually no seismic activity at MSH in recent weeks. A few very small tremors have been recorded, but nothing of any consequence. The Volcanocam cameras are both operational, although the HD camera is still showing some bizarre colour effects at times. The images today show the crater obscured by clouds, with only the lower flanks of the mountain visible. The weather is likely to remain less than ideal, with snow forecast for the next week.

13 May - A number of larger quakes have been visible on the Mount St Helens webicorders over the last 24 hours, although none are associated with MSH, which has remained quiet. This morning there was a small M2.5 tremor near Amboy, WA at 6:33 PDT, which is clearly seen on the CDF webicorder trace. Last night there was an M5.1 quake off the coast of Oregon, which is also clearly seen on the CDF trace at 22:36 PDT. The other small quake on this last chart at 00:59 PDT (07:59 UTC) I haven't been able to identify.

07 May - A M5.1 quake off the coast of Oregon at 10:46 PDT appears on all of the MSH webicorders this morning. otherwise, seismic activity at MSH has remained at background levels. The Volcanocam cameras are streaming clear images of the crater, although the HD camera has developed some sort of funky colour problem...

04 May - Seismic activity has remained quiet over the last few days, and the weather continues to be fairly dismal at Mount St Helens. I have added a new video of the eruption of the Eyjafjallajökull volcano, constructed from images from the Mila webcam on the evening of 27 April 2010.

29 April - Things remain very quiet at Mount St Helens, with no significant events over the last few days. The classic Volcanocam suffered a power outage on Tuesday, but is back online now. Although the image feed shows only clouds... I have captured some night images from the Mila webcam following the eruption of the Eyjafjallajökull volcano two nights ago, which was quite active for several hours. The footage is choppy due to the slow refresh of the feed, but I am working on cleaning it up and hope to post it soon!

24 April - Seismic activity at Mount St Helens has remained at very low, background levels over the last week. There have been no events of particular note. The Volcanocam images have shown mainly cloudy conditions and snow in the Cascades. Tjis weather is predicted to continue into next week, with a small break possible tomorrow.

18 April - Seismic activity at Mount St Helens continues at background levels, with no events of note since the last update. There is speculation the the eruption of the volcano in Iceland may be beginning to subside, but in the meantime there are some spectacular images of the eruption posted around the web. e.g. see gallery - some of the night shots showing the lightning generated in the ash cloud are stunning!



13 June - All is quiet and a little gray -  clouds persist at Mount St Helens and seismic activity remains at very low levels. Similar conditions at Mt Redoubt at present. For an interesting bit of weekend reading, you may like this story in New Scientist magazine about the possibility of a super-volcano lurking under Mount St Helens...

Most recent noteworthy events

18 May - The weather remains clear at Mount St Helens, but seismic activity remains at background levels. The views of Mt Redoubt (Alaska) are partially obscured by steam/ash this morning. I have just posted a new animation using images from the Hut webcam at Redoubt in the movies section showing the growth of the lavadome over the last couple of months. Interesting to see rock emerge from the vent over this time frame!

11 May - The clouds and wet whether have returned to Mount St Helens, so the views of the crater are now very limited. Seismic activity remains low, with only a few small tremors seen in the webicorders over the last 24 hours. Activity at Mt Redoubt (Alaska) continues to provide interesting views, such as this dramatic image from the Hut webcam from last night.

22 April - Seismic activity remain muted at Mount St Helens, and more clouds have moved into the area and obscured the view on the Volcanocam images. However, there is some developments from the Mt Redoubt (Alaska) webcams. On the night of 20 April several bright flashes can be seen on the webcam images! I have generated a small animation of the images from early in the day on the 20th until day time on the 21st. There's quite a bit to see in these animations - first of note is the large ice/snow collapse on the first day, the waterfall running in the lower centre of the frame and then the glow from rock falls in the growing lavadome. The first animation shows the night images at the actual brightness of the original images and its a little difficult to see. The second uses image processing to greatly enhance the glow and superimposes the glow on a reference image of the crater. Enjoy!

13/14 September - There were no significant changes overnight, but I have compiled a video of the last few days, which is available in the movie section. Lots of dust and several small rock slides on the crater walls are visible, as are a couple of visitors to the Volcanocam - LOL!

04/05 July - Another cloudy night with little activity to report. The large M7.7 quake in the Sea of Okhotsk is clearly visible on all of the webicorders just after 19:20 PDT [e.g. see JUN, VALT traces].

02/03 July - A thunderstorm passed over Mount St Helens last night and both of the Volcanocam cameras recorded lightning strikes on the mountain. The classic at 22:56 [see image] and a much better and more detailed image from the HD camera at 23:07 [see image]. You can also see the passage of the storm over the mountain as a band of increased background noise on the webicorders between 23:00 and midnight PDT. [e.g. see VALT, SWFL, JUN]

19/20 June - The sky was relatively clear and the moon once again illuminated Mount St Helens overnight, but activity within the crater remains at very low levels. I have posted an animation of Wednesday night's images in the Movies section. The full moon is overexposed in the HD Volcanocam images and looks far larger than it should. There are also numerous contrails from passing aircraft visible in the evening and night sky passing over Mount St Helens - perhaps adding weight to the idea that the bright lights seen over MSH on the night of 13 June may have been aircraft lights?

13/14 June - It was a clear night and there was no interesting activity from the crater of Mount St Helens, but there was something happening in the skies above! Around 02:21am this morning there was a bright object visible for a brief time - possibly an aircraft, satellite or fireball? I have also posted a movie of the complete night, from sunset to sunrise in the Movies section. Anyone have any idea what it may have been?


Note:  All available movies of the nighttime activity of Mount St Helens, from 2004-2007 can be found in the archives



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