Topics (384k) Articles (398k) Users (410) Discussions (242) Comments (383) Files (13k) New article
Peter M. Shearer coauthored a method for inferring focal mechanisms from P wave first-motion polarities. It varies source location and the velocity model, collecting acceptable mechanisms rather than treating every ray direction as exact.[ref]
The spread of acceptable solutions measures stability of the inference and helps distinguish real fault-orientation variation from measurement uncertainty.
Barry Parsons coauthored an analysis of how ocean-floor depth and heat flux change with age, using those data to compare models of cooling oceanic lithosphere.[ref]
An analysis of the variation of ocean floor bathymetry and heat flow with age by Barry Parsons and John G. Sclater. Abstract: model comparison and observational constraints
John G. Sclater coauthored work linking ocean-floor depth and heat flux to the age of oceanic lithosphere. With Barry Parsons, he compared cooling models against both types of observation.[ref]
An analysis of the variation of ocean floor bathymetry and heat flow with age by Barry Parsons and John G. Sclater. Abstract: cooling/plate models tested with depth and heat flow
Cooling changes both the thermal gradient that drives heat loss and the mass density structure that affects subsidence. Their joint use constrains the thermal evolution more strongly than either observation alone.
S. J. Mackwell investigates the mechanical behaviour of planetary materials through laboratory deformation experiments. His work on hot, dry rock connects measured stress and strain rate with the strength expected in the crust of Venus.[ref]
High-temperature deformation of dry diabase, with application to crustal deformation on Venus by S. J. Mackwell and others. Experimental and textural study of high-temperature deformation
R. D. van der Hilst uses seismology to investigate Earth's interior. His teaching develops the connection between measured seismic arrivals and wave propagation, while his research includes global seismic tomography used to constrain mantle circulation.[ref]
Essentials of Geophysics: Seismology by R. D. van der Hilst. Course notes: seismic propagation and Earth structure
[ref]Evidence for deep mantle circulation from global tomography by R. D. van der Hilst and others. Abstract: mantle structure from global tomography
The inferential step is important: a wave-speed anomaly is an observation-dependent model, and interpreting it as temperature, composition or flow requires additional physical assumptions.
F. Waldhauser co-developed double-difference earthquake relocation with W. Ellsworth. The method combines ordinary arrival-time data with precise waveform-based differential measurements, then adjusts relative source positions to fit those differences.[ref]
A Double-difference Earthquake Location Algorithm: Method and Application to the Northern Hayward Fault, California by F. Waldhauser and W. Ellsworth. Abstract: combined catalogue/cross-correlation observations and iterative solution
Closely related waveforms provide useful timing information through cross-correlation. Combining those observations with a network of stations can reveal structure within a seismic cluster that a collection of independently located events would blur.
W. Ellsworth co-developed a double-difference earthquake relocation method with F. Waldhauser. Their algorithm compares differences in arrival times from nearby earthquakes recorded at common stations, reducing errors shared along similar propagation paths.[ref]
The result is improved relative location within an earthquake cluster, rather than an automatic exact absolute position. The distinction helps interpret fine fault geometry without confusing relative precision with the accuracy of the underlying velocity model.
H. F. Reid developed the elastic-rebound theory of earthquakes from deformation associated with the 1906 California earthquake. The theory connects slow accumulation of elastic strain with sudden fault slip and release of stored energy.[ref]
Reid's Elastic Rebound Theory by United States Geological Survey. Surface-displacement observations and the elastic-rebound interpretation
An offset marker records displacement during rupture, while measurements spread over a broader region reveal the preceding deformation. These are complementary observations: the final offset alone does not describe the full volume of rock that stored elastic energy before the event.
A researcher who coauthored an analysis of sexual dimorphism and extinction patterns in fossil ostracods. The interpretation used body-form differences as a proxy for reproductive investment, making the proxy assumption part of the argument.[ref]
High male sexual investment as a driver of extinction in fossil ostracods by Maria João Fernandes Martins and others. 2018, dimorphism and extinction estimates
A researcher who coauthored mark-and-recapture studies of host-associated apple maggot flies. Measuring movements among host plants helped estimate a barrier to mating before fertilization.[ref]
A researcher who coauthored genetic mapping of host adaptation and habitat preference in pea aphids. The study connected ecological specialization with potential barriers to gene exchange.[ref]
A researcher who coauthored genetic mapping of mating preferences in Heliconius butterflies. Comparison of preference-associated regions with wing-pattern loci helped investigate how traits and preferences remain associated.[ref]
A researcher who coauthored research relating visual pigments, light environments and mating preferences in cichlids. The comparison connected ecological conditions with a proposed mechanism of reproductive isolation.[ref]
A researcher who coauthored a framework distinguishing questions about causation, development, survival value and evolutionary history in ethology. These are complementary questions about a behavior rather than competing names for one explanation.[ref]
On aims and methods of Ethology by Nikolaas Tinbergen. 1963, four classes of explanation
A researcher who coauthored experiments on obstacle avoidance in flying bats. Sensory manipulations connected acoustic information with successful flight around obstacles.[ref]
The sensory basis of obstacle avoidance by flying bats by Donald R. Griffin and others. 1941, sensory and acoustic experiments
A researcher who coauthored experiments on reward-induced changes in bumblebee responses to ambiguous cues. Behavioral tests and dopamine manipulation connected a change in state with several measured outcomes.[ref]
Unexpected rewards induce dopamine-dependent positive emotion-like state changes in bumblebees by Clint J. Perry and others. 2016, reward, ambiguous-cue and manipulation experiments
A researcher who coauthored experiments comparing chimpanzee responses to different human actions that produced the same withheld-food outcome. The matched outcomes helped distinguish responses to actions from responses to food availability alone.[ref]
A researcher who coauthored experiments on food competition in chimpanzees. Occlusion and access controls tested whether choices tracked what another individual could see.[ref]
A researcher who coauthored experiments on cache protection when ravens could hear but not see competitors. Prior peephole experience helped test the role of inferred visual access.[ref]
Ravens attribute visual access to unseen competitors by Thomas Bugnyar and others. 2016, peephole and playback conditions
A researcher who coauthored comparisons of chimpanzee performance in knowledge–ignorance and false-belief tasks. Matched competitive situations helped distinguish success on one task from evidence for the other capacity.[ref]
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact