Mar 8, 2007
The last time I commented on this one the Topix connection crashed. Suffice it to say that the fact that neutron stars hover mostly around 1.3 to 1.4 solar masses indicates a difference in formation mechanism between neutron stars & stellar mass black holes. The Magnetars may be a bridging mass mechanism between classic neutron stars & black holes but in their case they should be formed in classic type 1 supernova collapse and be dumped on by the inner part of the outer layers with the ejection velocity of the outer shell a mite lower than average for a type 1. SN 1987A appears to have produced a magnetar (will need to wait for the debris to clear a bit). The stellar mass black holes may have a completely different core convection feeder structure to a classical supergiant. Best guess so far appears to be an infalling equatorial disc carrying cool fusible material into the core & a polar outflow rich in fusion products cycling back into the equatorial disc. Problem rests in an upper mass cutoff for neutron stars (magnetars) and a lower mass cutoff for stellar mass black holes. have a nice day: Ag (Wednesday May 15 | post #1)
Nice article. This is the bit where the queen charlotte islands rift comes onland at the point where it is overridden by the North American plate and becomes an onland rift all the way up to Mt. Edziza. One arm of the rift is the queen charlotte islands & Haider Gwaii, the other arm of the rift is the NW, part of vancouver island. Both of the outer arms are bounded on the Pacific side by megathrusts. The Behm canal bit of the rift is notable for a large airfall tuff from an unknown volcano. This pretty pic may show the progenitor cone. The megathrusts bounding the outer rift arms are also interesting for a different reason. The last megathrust case both in the Garibaldi arc (BC) and the E.Alaska coast (Haider Gwaii, Canada & NW into alaska) last produced a magnitude 9 in the early part of the Holocene or latest Pleistocene and bound backarc basins capable of producing large runout values and large tsunami runup values. Have a nice day: Ag (Wednesday May 15 | post #1)
Nice article. As a result of the magnetar being traceable via its period it will be an independent indicator of orbital velocity around the black hole. Will likely be rather handy in pinning down the mass of sgr A* in the tens of thousands to thousands of solar masses bracket, and being X ray it will also be rather more resolved than the IR views of the nearby bright stars. Would also probably be able to notice the flares as the magnetar crashes through the equatorial drag & spin disc of the supermassive black hole, as sgr A* & the magnetar will not have a similar rotation axis & will precess & different rates & directions. Have a nice day: Ag (Wednesday May 15 | post #1)
Have been motorbiking in the 80s & 90s. Been there done that. The greenfly & occasional mosquito I can cope with but the fuzzy orange shite flies & stink bugs taste bloody awful. This is one of the reasons why motorbikers look dour & seldom smile... Have a nice day: Ag (Wednesday May 15 | post #3)
Interesting result. The fun bit is that if we were not so close to a magnetic reversal, the difference in spin of the core versus mantle would have been known about, tested & proved in the 50s. This difference sets up the currents in the liquid core that produces the dynamo dipole magnetic field. The fact that we still have a dipole field is probably due to a difference in velocity between the outer & inner core. The chaotic mantle rotation velocity differences caused by descending plate lurch (as in Tohoku 2011) appear to be responsible for variations in the current dipole field strength & direction of magnetic poles. There has been a few of those big rebound/long duration mercalli X (r/lx) quakes recently beginning in 2004, all of them (2004, 2010, & 2011) have relaxed the crust of the overriding & descending plates and produced a descending plate lurch. Have a nice day: Ag (Wednesday May 15 | post #1)
Forget fines as a deterrant. The boss of the company involved should do jailtime. Have a nice day: Ag (Wednesday May 15 | post #1)
About time too. This volcano (like cleveland) is squeezing in a long subvertical magma filled fracture formed during rebound /long duration mercalli X (r/lx) quake of the 1780s, which produced a bloody great big tsunami @ Sanak island wiping out an Aleut village in historically documented reportage (and several others where no reports came in). 2 quakes in quick succession are listed on the NOAA website. The r/lx relaxed the crust from E. Unimak to W. Kodiak, and the long fractures at the base of the crust & solid upper mantle now hold the magma squeezing into the Aleutian-Alaskan peninsula volcanoes in that sector. As the vector appears to have been approximately S. the fractures extend into the backarc to the W. and hit the arc @ the E. where the volcanoes happen to be. Pavlof, Cleveland, Shishaldin and several others squeezing in the long fracture set from the W. have the highest convergence rate to the W. and the slowest @ the E. so the long fracture set eruptions tend to be relatively regular, building up a sharp & quite pretty cone at the volcano on top of the E. part of the fracture which is the least compressed bit. Nice to see that Pavlof is almost to schedule as far as tectonic convergence goes... Will keep watching that space. Shishaldin appears to be somewhat close to the end of an average interval gap @ present, so may show up as a small eruption in the next year or so. For the record the same 1708s r/lx opened the fracture set that fed the Novarupta eruption (1912), Drained the katmai magma chamber into the open fracture top & also via a parallel fracture fed the adjacent Trident volcano new growth cone. Most earthquake research in the region appears to focus on recompression quakes in the forearc of this r/lx sector. The volcanoes will (when they shut down) indicate the likely time of the next r/lx in that sector. dr. G.Pflaker take note... volcanoes are important indicators of M9 & M9+ r/lx events in megathrust bounded subduction zones. Volcanoes however will not predict forearc & arc recompression earthquakes; BUT, a propagating magma filled fracture causing dilation of the deep crust & upper solid mantle is likely to cause a thrust quake in the forearc segment adjacent to a volcano prior to its arrival @ the volcano. This latter effect is relatively common in the late stage of recompression of an arc prior to r/lx and will result in high volume eruptions of gas rich magma as the untapped magma filled fracture finally hits the surface via the volcano. This has happened in Indonesia in historic time, and may have shown up in the late prehistoric 14C record of the Aleutian arc & Alaska peninsula. Have a nice day: Ag (Wednesday May 15 | post #1)
Interesting article. The variable nature of local subsidence following Rebound/long duration Mercalli X (r/lx) events @ cascadia has been documented in palaeotsunami studies in Cascadia over the last 8 years. The problem comes in the reportage which was definitely NOT available to the wider geoscience community during the Bush regime years (in large part because publishing authors tended to get as buried as the work they reported on). This has resulted in few works coming to press outside the USA on easy access. The result of summing up 14C dates for all the basins however did result in a series of several entire Cascadia crossing events (of which the 1700AD event was the last), and with variable runout the, tsunami runup and also the subsidence of the various coastal sectors did not reveal the size of the runout of each crustal relaxation event. The research also on summing up did however indicate several smaller events nucleated in the S. of cascadia (Nor Cal) and extending partway up the Cascadia zone resulting from spreading into the Basin & range of the Gulf of California rift. The result has been a variable interval time between quakes with the shortest interval time in the S. and longest in the N. with a typical runout vector being either NW. or WNW. and the fastest arc convergence also in the S. part of Cascadia nearest to the gorda arc (Mendocino region) junction box near Mt. Lassen. The 1700AD r/lx may actually have had a W. vector, but crustal relaxation results post 1700 indicate WNW directed backarc crustal relaxation through the colorado hotspot & the New madrid region & eventually the Charleston rift (these latter 2 events historically documented). The longest interval time appears to be in the far NW at the junction box with the garibaldi arc, with thus far the forearc near Silverthrone volcano (BC Canada) being r/lx free throughout the bulk of the late Holocene (about 5000Bp to present with the sea level @ or near the current interglacial highstand) , and the forearc block [the area of W. Vancouver island] being swept by teletsunami from Cascadia and Alaska rather than being hit by a local tsunami from a home grown Garibaldi arc r/lx. Cascadia r/lx covering the whole subduction zone has occasionally hit the E. part of vancouver island forearc block as in the 1700AD event. The interesting bit to come appears to be the squeeze out of magma from the Chilcotin hotspot (Wells Grey-Clearwater volcanic field),as a result of recompression of the Chilcotin backarc basin to the magma filled fractures near the backfault controlling hotspot, indicating a possible near future (a few centuries), r/lx beginning @ the garibaldi arc near silverthrone volcano & extending all the way to California via Cascadia with a SW. vector relaxing the Chilcotin backarc basin & the bulk of the Cascadia frontal part of the basin & range causing a SW. lurch of the N. American plate. That one would be bigger than average and likely followed in relatively short term by an r/lx nucleated in N.California and crossing a small sector of the S. part Cascadia likely terminating in Oregon. Being a junction box of hotspot controlled backarc basins spreading @ variable rates the date of the next r/lx & its vector will be as difficult to pin down as the size of the preceeding events. Interval time in reportage so far has been anywhere from 280 years to 1200 years in the listed holocene record in the available reportage. The variation in vectors is the root cause of the heterogeneous results of tsunami size and associated coastal forearc subsidendce. Have a nice day: Ag (Wednesday May 15 | post #1)
Looks like it is about to grow a new intracrater dome. Will keep watching that space. Have a nice day: Ag (Monday May 13 | post #1)
El Popo "Pops" again. Have a nice day: Ag (Monday May 13 | post #1)
Nice pic. Background info was impressive in the fact that this galaxy has a visible diameter similar to our own. I was expecting this one to be bigger. Appears to be more compact & massive than ours. M77 is not quite face on (appears to be about 25 to 20 degrees tilted and may be a foreshortened barred spiral). The impressive bit is the degree of resolution as most of the photos seen previously showed a bright central blob and a fuzzy outer set of arms with little structure. No sign of an interacting companion, but there is a more distant spiral seen through the left quadrant of the outer spiral arm (shows as a small amber spiral). Have a nice day: Ag (Monday May 13 | post #1)
Nice pic. Still no Whodunnit but plenty of prime suspects for the background glow. Sad news is that being very long wavelength it is difficult to assign a redshift to the radio sources via the radio emmisions. May not correspond to the visible light @ the same dot on the map. May get a different glow at different close wavelengths (22, 23 or more cm rather than 21cm for example). Will keep watching that space. have a nice day: Ag (Monday May 13 | post #1)
Nice pic. So that's why there are currently so few earthquakes at new moon. Gives me a chance to tidy up my seismicity record extracts without new ones getting in the way. Will likely be more quakes per day in 2 weeks time. have a nice day: Ag (Monday May 13 | post #1)
This one is kinda handy as the prior articles in climate in particular were reporting a smaller than expected solar max following the small blank sun of ~3 years duration during the last solar superminimum. This superminimum was a result of all the beat periods superimposed on the classic 11 year average cycle all converging on a minimum @ the same time. This article indicates that earlier this year one of the beat periods got in the way of totalising results. All told it is likely this cycle that it will be a near mirror image of the last double peaked solar cycle with the 2nd peak being warmer in our small blue dot on the map. Will keep watching that space. have a nice day: Ag (Monday May 13 | post #1)
I like that article. The other fun bit is that they got lucky in the fact that the Hyades cluster is relatively young and also metal rich (anything heavier than H & He). Another good place to hunt for similar results is the slightly younger & equally metal rich Praespe cluster and also the Coma Berenices cluster. All of these clusters are of similar age and all have higher metallicity than the sun. The article also implies asteroid herding by a more distant gas giant planet, so a 2nd discovery post may pop up involving the same white dwarves later when HST gets its astrometrics worked out. The star as a classic AGB giant would be similar to delta Apodis, and ultimately apha Herculis in size, so a gas giant would be stable in an orbit at about Saturn distance, The red giant would engulf anything within Mars distance as an AGB giant of Mira type and scorch anything at Jovian distance down to bare rock. The star as an AGB giant would also spend a small amount of time as a star of C type, getting smaller & hotter with time on the way to forming the central WD; so the Si rich rock would be in a belt at or less than Jupiter distance from the star, and anything further then Jupiter distance would condense C and transition metals along with the Si into the outside of any asteroids already present. Have a nice day: Ag (Monday May 13 | post #1)
Geologist [I'm Climate Change]
NEIC global earthquake list. Smithsonian Inst: Global volcanism program. Local area sites in geological event areas (see believe in).
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nobody at all:(this following a science blacklist under New labour since 1999, and a 100% employment blacklist by the same idiots since 2001).
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on web gathering science info (Geology & Meteorology). Also now preparing to emigrate with father to new EX UK address.
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Absolutely nothing at all. B.Sc 2:ii Geology, Aberystwyth 1987 P.G.Diploma Advanced manufacturing Technology, Nottingham Trent Univ. 1989 M.Sc DIC Petroleum Geology, Imperial college 1999. I am emigrating in response to the Blair/Brown/Bush employment blacklist versus science/engineering since 1997, and its discovery in 2005 preventing employment in all but their lowest level criminal rehab (refused then & now).