Search results

  1. B

    Article in Nature On Global Temperature variability

    I don't think it "addresses the inaccuracies of prior climate models". It looks at variance in an ensemble of prior climate models with known ECS parameter to establish a relationship which is then used to estimate the true ECS parameter.
  2. B

    Article in Nature On Global Temperature variability

    Interesting article evo, thanks for bringing it up. My reading of it is that the ECS parameter is now more confidently known in such a way that the 66% confidence interval is now tighter than it was in the previous IPCC report. In fact the maximum likelihood value of ECS is about the same...
  3. B

    New York Flood Risk through 2300 CE

    Ah, you misunderstood me then, it simply was meant as an exclamation of how cool and counterintuitive it was.
  4. B

    New York Flood Risk through 2300 CE

    Please clarify your point.
  5. B

    New York Flood Risk through 2300 CE

    This is another fascinating example of how intuition can lead you in completely the wrong direction. When an Ice Sheet melts sea level drops locally? No way!!
  6. B

    Phase relation for mantle?

    You would also need to know the composition. Often a pyrolite composition is assumed for the Earth's whole mantle. You might want to look at some equations of state the Birch-Murnaghan equation of state is often used in geophysics. You may want to see how some open-source software can help...
  7. B

    Liquid Regions of Mantle May Underlie Plumes

    Dave I know you know and by no means was challenging your clearly very high intelligence! :smile: I just wanted to make sure, for the record, that no one came away with the misunderstanding that the mantle was in any way not a solid. It's a common misconception. I remember, I was taught in a...
  8. B

    Liquid Regions of Mantle May Underlie Plumes

    BTW, interesting topic and nice study... I will report back once I've had time to read the actual paper. EDIT: added a brief report. Ok so the seismology is very convincing. There is definitely something down there right at the base of the Iceland plume, and that something is definitely...
  9. B

    Liquid Regions of Mantle May Underlie Plumes

    The mantle is solid dave! Otherwise how would shear waves go through? It's not rigid, and deforms visco-plastically, but it is solid!
  10. B

    What does Wavelength have to do with Crustal Structure?

    No worries @jim mcnamara -- here's a starting point:
  11. B

    Drilling into an Earthquake Fault

    I dunno, sounds pretty cool to me! It's not just any fault: it's a fresh -- seismically active -- fault!
  12. B

    What does Wavelength have to do with Crustal Structure?

    The wavelength is simply the spatial extent of the gravity anomaly. A gravity anomaly that spreads over a large area has a large wavelength. If the lithosphere were infinitely strong then a load would not cause a local depression (and hence a localised "short wavelength" gravity anomaly) but...
  13. B

    Rethinking the Earth's core

    In terms of the "light" element in the core. It is important to reiterate that we are talking about ~5%. Nobody doubts that 95% is made of iron and nickel.
  14. B

    Rethinking the Earth's core

    Because we make a model of the Earth that includes a solid core and predict when and where the energy from an earthquake would arrive. Then we look at seismic recordings of all the earthquakes that have ever got recorded and we see that our model fits the data (it predicts what we observe)...
  15. B

    Update on Tectonic Plate Dynamics

    Very interesting subject. My criticism would be that it seems bit circular. They use their model to show that the Earth is not as expected if the preexisting hypothesis is true. Then they use the same model to support their alternative hypothesis. At least that's my understanding...
  16. B

    Earthquake science book

    As a student of seismology I found "Introduction to seismology" by Peter Shearer to be a clear concise read. As a post-doctoral seismologist I still find it to be a useful reference.
  17. B

    How do the continents float?

    What makes you think the continents and the oceans are floating on magma? The oceanic lithosphere is denser than the continental lithosphere, hence it is lower.
  18. B

    Earth's inner core has an inner core of its own

    Hmmm, an interesting use of the increasingly popular "seismic interferometry" technique.. The "inner inner core" is nothing new, it's been around for over 10 years now. So most of the media hype is just that, hype. Previous work has suggested that this inner inner core can be explained away by...
  19. B

    20140925 Solomons Quake

    Hi Dave, what distance are you from the quake? What body wave phases can you identify? Which component is this, vertical?
  20. B

    Mount Tavurvur eruption, 2014

    That boom is so awesome I've embedded it below. Thanks!
  21. B

    The Sliding Rock Phenomenon

    A new paper claims to have finally solved this one: See also, blog: and university press release...
  22. B

    Most Recent Changes in Earth's Magnetic Field; Sources Analyzed

    Perhaps the title should read: "Most Recent Changes in Earth's Magnetic Field; Sources [b]to be[\b] Analyzed."
  23. B

    Water injection to defuse big quakes

    The point is that if action you take does not fundamentally deal with the problem, then you are wasting your time. What if we live along the same fault line and my backyard is preloaded with stress. You unzip the stress in your backyard and bring the stress in my back yard closer to...
  24. B

    Water injection to defuse big quakes

    I guess the other technical issue is what effect does doing this have on the stress regime somewhere further down the line? Are you not just shifting the problem onto someone else's doorstep?
  25. B

    Water injection to defuse big quakes

    Agree. But how do you incentivize someone to do it? The reward that you might save lives in the future is not enough IMO, at least not on a personal level, because you have to offset that with the risk that you could inadvertently take lives. Fair enough if we had the technology to make it...
  26. B

    Water injection to defuse big quakes

    I agree with dave on this. How exactly do you propose to trigger 30 Mw 5.0 events/day? We don't have the knowledge/technology to do it. Who would be prepared to risk being held responsible for triggering a destructive Mw 7.0+? The incentives are not there. If you get it right, you're just...
  27. B

    PhD doubts

    Coming from geophysics I'd recommend you to read review papers (I assume you have those in physics). These will give you the overview and are an excellent source of references for more detailed reading should you need it. Obviously the more up-to-date the review the better, generally speaking...
  28. B

    Seismic T-waves

    I would hazard a guess that it has to do with geometrical spreading. The normal P wave propagates with a spherical wavefront and so loses energy in proportion to 1/R2. Whereas the T wave is trapped in a layer and so propagates out cylindrically losing energy in proportion to 1/R...
  29. B

    Seismic T-waves

    Hi Dave, awesome observation! So based on the little reading I did, I guess the quake would likely have been a "fast" one? (which I guess has something to do with a high acceleration of ground motion at source) I first became aware of the so-called "T-wave" at this year's fall AGU conference...