When you want to see the stars, find someplace dark
Supposedly common, I have been poking about in caves for over four years without seeing these attractive lobsters. In this cave were several of them. I caught this guy in a corner, he wanted to get past me, but could not get past the light. Good thing for him it isn’t lobster season.
Dan Birchall is at it again, using his vantage point at Subaru to shoot time lapse of Keck and some other telescope using lasers over the summit of Mauna Kea…
I understand it was quite the scramble, but both telescopes are back on-sky tonight.
The earthquakes started just after two this afternoon with the magnitude 4.5 event that got our attention so quickly. This gave day crew three hours to have everything inspected, checked out and ready for the night. Physical inspections, instrument checkouts, and more, an extensive checklist to follow and insure that no real damage was done by the temblors. Just after 5pm we got word that everything was good-to-go and both telescopes would be released for the night’s observing.
As of writing this, about ten hours after the first quake, there have been 32 separate events under Mauna Kea detected by the seismographs. A half dozen of those were near magnitude three. I have felt thirteen separate aftershocks, this plus the original quake makes fourteen, the most I have ever felt in a single day by a wide margin.
The USGS has released a statement noting that this was probably a “structural adjustment” a result of the enormous weight of Mauna Kea stressing the underlying rock…
Magnitude 4.5 earthquake on the north flank of Mauna Kea
By USGS/HVO
Hawai‘i Island, HAWAII—The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.5 earthquake located beneath the Island of Hawai‘i on Wednesday, October 19, at 2:10 p.m. HST. This earthquake was centered about 9 km (6 mi) northwest of Mauna Kea’s summit and 49 km (31 mi) west-northwest of Hilo, at a depth of 18.7 km (11.6 mi).
The earthquake was widely felt on the Island of Hawai’i. The USGS “Did you feel it?” Web site (http://earthquake.usgs.gov/eqcenter/dyfi/) received more than 500 felt reports within an hour of the earthquake.
The earthquake was the largest in a cluster of about 20 earthquakes on the north flank of Mauna Kea on Wednesday afternoon. Most of these aftershocks were too small to be felt, but, as of 3:30 p.m., two earthquakes with magnitudes greater than 3.0 had occurred in addition to the magnitude-4.5 event.
Over the past 25 years, the north flank of Mauna Kea has experienced 10 earthquakes greater than magnitude 4.0, including today’s event, at depths of 10–40 km (6–25 mi). Deep earthquakes in this region are most likely caused by structural adjustments within the Earth’s crust due to the heavy load of Mauna Kea.
Adjustments beneath Mauna Kea during past similar events, such as in March 2010, have produced a flurry of earthquakes, with many small aftershocks occurring for days after the main quake. Given this history, it is possible that additional small earthquakes may be recorded in the coming days.
Today’s earthquakes caused no detectable changes on the continuing eruption of Kilauea Volcano.
For eruption updates and information on recent earthquakes in Hawai’i, visit the Hawaiian Volcano Observatory website at http://hvo.wr.usgs.gov
This is starting to look ominous! Nineteen events so far and counting, it seems the building rattles every 10-20min with another aftershock. Will it please settle down?
Word is that Keck1 is fine, we are scheduled to do some engineering with the AO laser. The laser itself is still on and operational, a minor miracle. There may be some issues with Keck 2 after the initial quake. We are waiting for a more detailed report from the summit crew.
Ok? That was fun. A fairly serious quake right underneath us. A preliminary mag 4.5 centered between town and the summit of Mauna Kea. The building was shaking pretty good, with a series of hard and sharp shocks. I felt at least three aftershocks, though the USGS website shows five additional events in quick succession at much the same location and depth.
We had a few minutes to enjoy a beautiful sunny day in Waimea, as all of the Keck staff waited outside for the shaking to stop.
Watching sunrise from the summit of Mauna Kea is often the highlight of many visitor’s trip to the island. Any given morning will see a handful of tour vans and rental Jeeps atop the summit ridge awaiting the first glint of sunlight. A small crowd of camera wielding tourists mill about, gazing at the spectacle or huddle in vehicles to avoid the bitter wind.
I do occasionally stop to watch myself. While the telescope operators head for breakfast down below. I stop and join the crowd for a few minutes. Sometimes you just have to take a moment and enjoy the privilege of working in a place like Mauna Kea.
Click on the image for a better appreciation of what it is like to be there… Without the wind.
With my face behind the camera, and looking the other direction, I did not notice the commotion I had caused. A swirl of colorful motion caught the corner of my eye. I turned to see a horde of butterflyfish attacking a seemingly uninteresting rock face. I watched for a moment before a memory triggered… Of course!
It is likely the gang of butterflyfish used my presence as an opening to overwhelm the Sergent. Local lore is full of examples of this behavior. The passage of a larger predatory fish, or a diver, will give the guarding male Sergeant a pause. A slim opening upon which the gang will swarm the eggs and feed. During Sergent breeding season it is not unusual for divers to mention schools of butterflyfish or tangs following them in and around the nesting areas.
I literally have to push my way through the swirling fish to examine the nest. The rock is covered with eggs, an amazing number of little purple dots covering an area of about a meter square. Despite the ongoing feeding frenzy, the nest seems intact, with nearly every bit of the rock covered with the neat little lines of eggs.
Hoover1 makes an interesting observation… “One can only wonder why Sergent eggs are so conspicuous while most damselfish eggs are hardly visible”
1) Hawaiian Reef Fishes, John P. Hoover, Mutual Publishing, 2008
A world shrouded in hydrocarbon smog, where there are rivers and lakes collecting methane rain. Despite numerous flybys of the Cassini spacecraft and landing of Huygens probe on the surface, Titan remains a very mysterious world. A thick atmosphere and exotic chemistries create conditions that might even harbor some form of life.
Taken from this angle, the view looks toward the side of Titan that always faces away from Saturn. Keep in mind that Titan is 5,150 kilometers (3,200 miles across), much smaller than the Earth, but quite a bit larger than our Moon. The image was taken with the Cassini spacecraft narrow-angle camera on Aug. 9, 2011 using a spectral filter sensitive to wavelengths of near-infrared light centered at 938 nanometers. The view was acquired at a distance of approximately 1.4 million kilometers (870,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 35 degrees. Image scale is 8 kilometers (5 miles) per pixel.
