Don't Panic Geocast

Last week we talked about glaciers, a basic staple of any geology education. That means it’s only fair to talk about a geophysics staple this week. We can measure gravity at different locations and use it to help figure out what’s under our feet. That and another great Fun Paper this week! It’s All About Pentiums (Weird Al) Gravity Basics All geophysical methods are based on measuring some kind of physical property difference. Gravity is sensitive to the density of the material below the measurement. “Big G" gal (unit) Density for any rock varies widely. Gravity from impact structures Measuring gravity Absolute gravimeter Relative gravimeter Zero-Length Springs Differential GPS Corrections Examples of the more common corrections Eötvös effect John’s explanation of Coriolis Force and Toilets Isostasy Bouguer Anomaly FORTRAN Talwani Example Original Talwani Paper Fun Paper Friday Alarcón, Héctor, et al. “Self-Amplification of Solid Friction in Interleaved Assemblies.” Physical Review Letters 116.1 (2016): 015502. Semis pulling on phone books Mythbusters Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

Last known survivor of the 1906 San Fran. EQ/Fire passes away Ice is a mineral National Snow and Ice Data Center Great USGS informational publication on ice ages Mendenhall Glacier Video of 1 year of Mendenhall melting Chasing Ice Firn Pressure melting point Regelation Video of Regelation Experiment Weertman 1957 (Paper on ice movement) Great Lakes Glacial erratic Ice age Drumlin Esker Moraine Kettle Lakes Subglacial channels Glacial striation Fun Paper Friday This week we learn about low frequency sound waves in the atmosphere and how we can use them to determine the winds at high altitudes and improve numerical weather prediction. EOS Article Arrowsmith, Stephen J., Omar Marcillo, and Douglas P. Drob. “A framework for estimating stratospheric wind speeds from unknown sources and application to the 2010 December 25 bolide.” Geophysical Journal International 195.1 (2013): 491–503. Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

Last week we told you about many different map projections and talked about why they are all wrong. This week we’ll discuss a few of our favorites, why we like them, and when they fail us. We also have another Star Wars themed Fun Paper Friday! How’s your 2016 so far? (PhD Comics) Nuclear Test John’s Particle Motion Movie How To Detect A Secret Nuclear Test Picking a Projection Consider what you need For dot density plots, equal area is important Mercator projection Gnomonic projection Great circle distance Great circle Our Favorites Compare landmasses to Africa. Mercator puzzle Wikipedia lists over 60 different projections! Strangest: Hammer retroazimuthal projection or Waterman Butterfly Projection Most boring/overused: Mercator Projection or Web Mercator Pleasing whole-world: Robinson , Winkel tripel projection, or Armadillo Polar Regions: Stereographic Projection or Pierce Quincuncial Projection Fun Paper Friday Feinstein, Zachary. “It’s a Trap: Emperor Palpatine’s Poison Pill.” arXiv preprint arXiv:1511.09054 (2015). Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

Maps are useful things, but it turns out that projecting a 3D object on a 2D map can cause a lot of unexpected problems. They even inspired an XKCD comic. This week we explore maps and map projections. We also chat about machine learning as part of #FunPaperFriday. What’s the big problem? The Earth is a sphere, actually it’s an ellipsoid, actually it’s really bumpy and messy Taking 3D information and pushing in onto a 2D medium means that you must sacrifice something, you are losing a dimension with which you can express information. Projections are a well thought out as researched problem, even in pure mathematics. You have to pick a projection that will tell you want you need to know accurately, and know that you lose some other information. There is even a West Wing clip about this A few examples of projection problems There are geographical properties that we care about: area, shape, direction, conformality, distance, scale… and you can’t get them all at once. In fact, some it’s hard to get more than approximately the right answer. Area: Maps that preserve area relationships between things on the globe are called equal area maps. Distance: Some maps (equidistant maps) show an accurate distance from the center of the projection to all points. Scale: The same scaling relation applied across the map will give accurate values for scale relations on the globe. Conformality: Scale in any direction at any point is identical. This means that parallels and meridians are at right angles. (Local shape preserved) http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html A few projections Projections can be generally classified as cylindrical, conic, azimuthal, or other. These are as you would think, projections onto cylinders, cones, planes, or with rules of “rectangular meridians” or something else. There are lots of sub-classes, you can view them here. Wikipedia lists over 60 different projections! Fun Paper Friday That’s what she said. Can we teach computers to better understand human speech patterns? This paper takes a humorous problem as a test case. Kiddon, C., & Brun, Y. (2011). That’s What She Said: Double Entendre Identification (pp. 89–94). Presented at the Annual Meeting of the Association for Computational Linguistics. Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

We want to wish you happy holidays and invite you to join us while John was at AGU. This show should have been released a week ago, but John got very ill at AGU and took several days to recover. Thank you for the well wishes and sticking with us! AGU Fall Meeting 5 Tips for Surviving your First Conference John didn’t get to see the Elon Musk lecture. He did get to sit in a car from Tesla Motors though. ObsPy Orbital Mechanics - Check them out! Fun Paper Friday Can plants remember and learn? The answer may surprise you, it did us! National Geographic Article Gagliano, Monica, et al. “Experience teaches plants to learn faster and forget slower in environments where it matters.” Oecologia 175.1 (2014): 63–72. Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

The holiday season is approaching and you may be wondering what to get that geoscientist or science nerd in your life. Look no further as we discuss our recommendations on the Don’t Panic gift guide! John’s Picks Gear Pedco UltraPod II AmScope SE400-Z Microscope Shower Mate Speaker MakerBeam Lowepro Extreme Padded Sport Backpack Books Thing Explainer What If? The Annotate Build-It-Yourself Science Laboratory, checkout author interview here Seveneves The Three-Body Problem Misc Geology Bed Sheets Audible Membership Dropbox Membership Soft Earth Pottery Geology Tricorder Shannon’s Picks Gear Garmin Monterra GPS Plateau Designs Field Pouch Rite in the Rain pouch and books UV/LED handlens Books and Movies Annals of a Former World Storm Kings Hyperbole and a half Jurassic World! DamNation Misc REI Chacos! Patagonia Messenger Bag Nikon AW110 Field Notes - snowblind! Fun Paper Friday Star Wars! Need we say more? Learn about Dunes and Tatooine with this week’s fun paper! Dunes on planet Tatooine: Observation of barchan migration at the Star Wars film set in Tunisia Lorenz, Ralph D., et al. “Dunes on planet Tatooine: Observation of barchan migration at the Star Wars film set in Tunisia.” Geomorphology 201 (2013): 264–271. Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

This week we continue our discussion of posters, presentation, and talk about splashing around with our fun paper Friday! Graphing Software Igor Pro KaleidaGraph Matplotlib Bokeh Veusz Poster Tools Inkscape Adobe Illustrator Adobe InDesign Adobe Color (Formerly Kuler) John’s AGU Talk Fun Paper Friday This week we talk about urine splashing and industrial uses of carbon nanotubes. Abstract: M32.00010 : Creating a urine black hole Phys.org with Videos Vantablack Article Vantablack Video Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

This week we re-visit one of our favorite shows while everyone is outside or in their turkey food-coma here in the US. We also read some listener mail about last week's episode on earthquake magnitudes!   Time is a very complex subject that you can devote your entire life to. Today we’ll cover a few of the basics and enough to get your interest up! We’ll see that it’s difficult to know what a second is and how long relative times are, but absolute time is even messier! We also discuss dried coffee and tetris! Importance of Time (and why it’s on a geology show) It synchronizes the world and our human interactions (need minutes - hours accuracy generally) It allows us to talk about events in a common coordinate system Allows synchronization of scientific measurements and comparison of data sources. This is really important for seismometers for EQ location! Let’s us use GPS! 1 billionth of a second (nano second) error in 1 GPS satellite, GPS receiver is +/- 1 ft to satellite, which is 2–3 feet on Earth. Early Timekeeping Burning candles in marked cases Hourglass Water powered clocks Pendulum clocks Galileo and Huygens (fancy temperature compensation as well) Video on Galileo Modern Time Keeping (Atomic Clocks) First clock was ammonia maser at National Bureau of Standards in 1949, but it really wasn’t all that accurate. It was more of a proof on concept device First cesium clock was in 1955 at the National Physical Laboratory (UK) Leads us to the definition of the SI second he duration of 9,192,631,770 cycles of radiation corresponding to the transition between two energy levels of the caesium–133 atom The NIST-F2, a cesium atomic fountain clock, is good to one second in 300 million years. How F2 works is a combination of feedback control loops, lasers, and really cold atoms. Remember, atomic clocks tick away seconds, they say nothing about the hours, minutes, seconds notation we use to write time. We just define a frequency Leap seconds Can’t predict them far into the future because of irregularities in Earth’s rotation Announced ahead of time in a bulletin by the International Earth Rotation and Reference Systems Service 25 leap seconds since 1972 Next leap second is this year! June 30, 2015 Real problem in computing, has caused software and GPS hardware crashes/issues before Google smears the second out over a period prior to the leap Time Standards There are TONS of time standards, we’re only going to touch on a few. Most are known with highest precision in retrospect! Solar time Exactly what you would think, it’s about using the sun’s position as a time source. There is the sundial time (apparent solar time) that changes throughout the year, and the mean solar time which is like a clock time. The equation of time represents the difference between the mean and apparent solar day Star clock International Atomic Time (TAI) A measurement of proper time (it’s a relativity thing) Weighted average of over 400 atomic clocks If there is an error, it isn’t corrected. This makes it into terrestrial time. Universal Time (UT) This is what we used to call GMT! Based on Earth’s rotation w.r.t different bodies (why there is UT0,UT1,UT1R,UT2,UTC) UT1 is really mean solar time at the equator Coordinated Universal Time (UTC) Formalized in 1960 Adjustments were accommodated by leap seconds starting in 1972 Generally considered to be GMT, but GMT isn’t defined/recognized by the scientific community This comes from TAI by accounting for leap seconds! Epoch time (Unix Time) Epoch time is the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970 No leap seconds by definition, but implementation is actually messy Stored is an integer (32-bits) meaning that it will run out and roll over on Tuesday 2038–01–19 One second after 03:14:07 UTC, it’s the year 2038 problem. The Timekeeper Video Audio after the outro is David Allen FunPaperFriday Coffee rings and coffee disks: Physics on the edge Particle shape controls movement during drying The can be applied to surface design, paints, and more Contact us: Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

This week we talk about Bill Nye, earthquake magnitudes, and coffee. Bill Nye John got to see Bill Nye (@BillNye) talk at Penn State! News article with photos! Earthquake Magnitudes Earthquake Size (C. Ammon) Challenge is that earthquakes span a huge dynamic range. We measure ground displacements over about 9 orders of magnitude. Largest Earthquakes in the World Since 1900 Kiyoo Wadati Richter magnitude scale Book: Richter’s Scale: Measure of an Earthquake, Measure of a Man Wood Anderson Seismometer Body wave magnitude Core Shadow Zone Surface wave magnitude Seismic moment Moment magnitude Example Seismogram Resources USGS Earthquake Notification Service Harvard GCMT emails and catalog Earthquake Storms - Dvorak Introduction to Seismology - Shearer An Introduction to Seismology, Earthquakes, and Earth Structure - Stein & Wysession Fun Paper Friday Do you like bitter tasting things? A study says that it tells something about your personality. Do you buy it? Article about paper “Black Coffee Equals Black Hearts" Sagioglou, Christina, and Tobias Greitemeyer. “Individual differences in bitter taste preferences are associated with antisocial personality traits.” Appetite 96 (2016): 299–308. Contact us Show - www.dontpanicgeocast.com - @dontpanicgeo - show@dontpanicgeocast.com John Leeman - www.johnrleeman.com - @geo_leeman Shannon Dulin - @ShannonDulin

This week Shannon is grading, John is modeling (numerically), and they both are mad about some graphs they have seen. Data Visualization We are colorblind Tableau20 Colors Rainbow Color Map (Still) Considered Harmful A Better Default Colormap (video) Perceptual Color Maps in matplotlib for Oceanography (video) Evaluation of Artery Visualization for Heart Disease Diagnosis (Borkin et al.) Make everything bigger than you think it needs to be! Resources Edward Tufte Flowing Data Visualize This (Book) Data Points (Book) The Craft of Scientific Presentations (Book) Presentation Zen (Book) Data Fluency (Book) Ask people that make things you like! Fun Paper Friday This week we talk about thundersnow and the Trump tower. How can buildings strike clouds? Warner, Tom A., Timothy J. Lang, and Walter A. Lyons. “Synoptic scale outbreak of self‐initiated upward lightning (SIUL) from tall structures during the central US blizzard of 1–2 February 2011.” Journal of Geophysical Research: Atmospheres 119.15 (2014): 9530–9548. EOS Press Release