Index 
To: mpngrove@comcast.net From: Scott Sinnock ssinnock@netzero.com 12:26am, September 10, 2013 Subject: Repentance Attached: Tertiary Temperature Graphs Mary Lou, I apologize for not being in “class” today, though perhaps that is for the better for some. Anyway, being absent, I felt I owed the teachers an apology, because you (and Bob who always diligently prepares for our benefit most informatively) express your heart-felt opinions from which I always drink deeply and even occasionally agree J. Don’t get a big head, the whole group is a source of inspiration to me, even perhaps a source of hope. But, being human I feel compelled to go further than an apology and provide an excuse for my negligent absence. I was working on the attached picture showing the earth’s temperature history for the past 70 or so million years. I want a comparative basis for evaluating claims about impending “catastrophes” because of “unprecedented” changes due to carbon burning, as I have often read and you probably have too. Anyway, busy in my research and its artistic presentation using Photoshop, I lost track of the time, looking up only at 2:30, too late for Political Focus. So too late to attend, I finished the picture. As part of my repentance, I am sending it to you to show I was a good boy diligently studying though not attending class. Bob, I am sure, can help interpret the attachment if needed. References are listed in the small text and resolution should be sufficient that zooming reveals them, but that’s not needed to get the gist. I could find no diagram like it, which is why I made it. Some conclusions, it seems to me, are obvious – for one, what’s a little temperature change to the juggernaut of evoluti on? Or, related, How important are we? Anyway I drift into polemics way beyond the facts, which the picture pretty well sticks to. As I was hunting for the right diagrams I ran across the following two pieces, one from 30 years ago and one more recent. I mention and include them only because I have often intoned in class and privately at least once or more to Bob that all scientific disciplines are not totally on board with the meteorite-impact hypothesis about extinction of the dinosaurs and lots of other things. I thought Bob and you might enjoy some of the “evidence”, which, after all, is just the opinion of some geologists. Physicists may be masters of the timeless, but geologists are the masters of time. First quote from the Proceedings of the National Academy of Sciences (one of my favorite good ole-boys clubs) by some of their distinguished members, paleontologists and zoologists of great distinction. Proc Natl Acad Sci USA. 2007 January 16; 104(3): 887–892. Item 1: Dinosaur Extinction: “There is little doubt that Mesozoic and Tertiary patterns in amphibian diversity were determined to a great extent by the diversification of the extant orders Anura, Caudata, and Gymnophiona (frogs, salamanders, and caecilians, respectively). Their evolutionary expansion throughout these periods has been described as a gradual process, apparently unaffected by large-scale environmental changes until perhaps the end-Eocene “Grande Coupure” in Eurasia (~35 Mya) and the Pleistocene glaciations (~2–0.01 Mya). Fossil data indicate a notable increase in amphibian abundance toward the present but, in contrast to the amniote record, provide no evidence for late Cretaceous and early Tertiary extinctions and radiations. Such patterns would be expected if amphibians living in these periods were as sensitive as their modern descendants to environmental change or if they took opportunistic advantage of postextinction niche vacancy, as has been proposed for modern birds and placental mammals.” abstract by Kim Roelants, et al. "Global patterns of diversification in the history of modern amphibians", Proceedings of National Acadamy of Science | AND Item 2: Stratigraphic Boundaries: “A rate of extinction must specify both the amount of taxonomic change and the duration of that change. A consistent means of temporal measurement must be used to establish the duration. Terms used to describe the extinction, like catastrophic and gradual, should be quantitatively defined in relation to this framework. Resolving rates of extinction in the stratigraphic record is limited by (1) the precision of chronostratigraphic correlations between individual sections and (2) the temporal completeness of litho- and biostratigraphic records in those sections. In this study, temporal completeness is estimated in eight of the best-known fluvial and pelagic sections spanning the K-T boundary. Temporal standardization is provided by correlations to the geomagnetic polarity time scale. A review of the literature documents lithologic criteria that might be used to infer the presence of a hiatus of some length at the biostratigraphically recognized K-T boundary. abstract by Lowell Dingus "Effects of startigraphic completeness on interpretations of extiction rates across the Cretaceous - Tertiary boundary" My physicist friends tell me that radiometric dates and geochemical signatures like iridium have solved the problem of uncertainty about when the K-T transition occurred, defined as the time of the demise of abundant fauna species. Well, not exactly. There is no, I repeat no site with multiple radiometric age dates whose average matches the “defined” number of 65.5 + or – 0.3 million years (Wikipedia “Cretaceous – Paleogene Boundary”) By the way, K-T is out, K-Pg is in. The first sentence of the Wikipedia article informed us of that “fact”, then ended with a appeal for eliminating the Tertiary Period with 5 epochs and replacing it with two periods, the Paloegene (the “Pg”) taking the first 3 epochs and the Neogene consisting of the last two, no change in any geologic system of rocks, just rearranging deck chairs on the Titanic. The average “age” of samples from any site representing “the boundary” doesn’t converge with more samples on the “true” value (or more precisely, “defined” number). It converges on its own number which may be 63 million years or 68 million or anything in between. With fewer samples, many sites have only one, the variance tends to increase (except it can’t for one sample), and variance “among” single-sample sites is huge. We put all the dates in a hopper, toss out the “obviously” bad dates, throw in some carefully selected weights to “correct” the remaining data for its “biases” including subjective litho-stratigraphic correlations, properly average the "weighted averages", and out pops the time of the K-T (oops, Pg) boundary of 65.5 + or - .03 million years, whatever that represents, noting an uncertainty range of about 60,000 years, about 1% which ain't bad. Also note that a geologic period is defined by a change in rocks, like beach sands that define the base of the Cretaceous or earlier Cambrian. Actually geologic periods are defined by the appearance of specific kinds of rocks called fossils or their environmental correlates (facies) if fossils are not diagnostic. The seas that made those beaches that supported those critters that became those fossils took millions of years to move across the continents with bays, estuaries, rivers, lagoons, beaches, dunes, marshes and every other coastal and near coastal sedimentary environment shifting, moving, exchanging, disappearing, reappearing, and forever changing. So the “beginning” of a period (which is defined geologically whereas the “ending” is not) changes in time with location, just as Antarctica and Greenland as well as northern Alaska, Canada, Europe, and Asia are still in the Pleistocene Epoch, the ice age, while we in Chicago live in the post-glacial Recent Epoch. Perhaps a date or series of dates associated with iridium and other geochemical spikes is zeroing in on the stratigraphic “hiatus” into which the fallout from a meteor settled, passing for the timing of the meteor’s impact, but not the time of the dinosaur extinction. Now as often happens when a sea moves over the land or a desert advances and ebbs (like during the Tertiary, see attached), the rocks we see are from areas (environments) more often eroded than areas serving as a final resting place for some sand grain or mud particle. Then the sea or desert may return, lay down a thin layer of sand or mud; recede again while the rains wash away the mud or sand it left behind and then some; return again long enough this time that the next retreat leaves behind some of the mud, but perhaps the next retreat, the next wave, the next flood or one 100,000 years later washes away even that deposit until finally a deposit covers a lower one that is never again eroded - creating the rocks we see. | Perhaps my bumbling explanation above will help translate the above articles which say that resolution of terrestrial rocks 50 to 100 million years ago is no better than 100,000 years under ideal conditions: the Caravada site in Spain famous for geochemical signatures of “the impact” and the San Juan Basin where “continuous” sedimentation occurred during that time. Geologists call it a “hiatus”, the time between when the individual layers of rock were deposited. As the author argues, it is difficult to claim evidence for a 100 or even 1000 year “catastrophic” event (e.g. dinosaur extinction, which some “impact” proponents say occurred in less than a year or so), when the resolution of your data is but 100,000 years at best. This imprecision is based on only one of two major sources of uncertainty identified by the author, “temporal completeness”, so is a minimum of minimums. The second source, “precision of chronostratigraphic correlations” may be even more significant. Rather than rejecting the presence of such gaps, this study argues that a hiatus of some length does exist and tries to estimate both a maximum limit for its duration and the probability that it represents a given duration below that limit. Pelagic sections are probably more complete than fluvial ones. The section at Caravaca, Spain can be expected to be the most complete, probably preserving sediments during each 10,000-yr interval of Chron 29R. Results indicate that our best-known marine and terrestrial sections spanning the K-T boundary should not be expected to document biologically catastrophic rates of extinction. A sufficiently precise means of global correlation that is independent of biostratigraphy and casual hypotheses is still unavailable, and it is very unlikely that the sections examined are complete at the 100-yr or biologically catastrophic level of precision. So, although catastrophic amounts of extinction might have occurred during the K-T transition, is seems unlikely that we can distinguish episodes of extinction lasting 100 years or less from episodes lasting as long as 100,000 yr. Consequently, acceptance of catastrophic hypotheses based on these stratigraphic records seems improbably optimistic at this time.” As I said in class, “So much conjecture from so little fact”. I hope to see you next week. Sorry for the long harangue, I get carried away sometimes as you know. Scott ATTACHMENTS: Tertiary and Holocene Temperature Histories, Showing Relative Industrial-Age Changes I made this graph after reading a newspaper article that predicted "unprecedented" temperature increases of up to 2 °C during the next 20 years and perhaps up to 4 °C in the next 100 years. Since then I have found one article based on GSM predictions that says a maximum increase of 8 °C is all that is possible, because increased cloud albedo would reflect a balance back to space at that temperature, cet. paribus. Originals: Industrial-Age Temperatures: From "http://ieet.org/index.php/IEET/more/treder2009052" (no longer active) Holocene Temperatures: From "http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/timpline.html" (no longer active) Cenozoic Temperatures: From "http://www.landforms.eu/carcinogens/Tertiary%2Dtemperature.htm" (no longer active) I rotated the Cenozoic graph to the right, inverted it, relabeled accordingly, and shifted the "Ice-free temperature" scale to the left edge and moved it to the top. |