If you have the means and want to do some good, donate to the Wonder Fund by @theAGU and @WomenDoingSci, which funds Black and Indigenous women in the geosciences to go to research conferences: womendoingscience.com/wonderfund
• • •
Missing some Tweet in this thread? You can try to
force a refresh
Today in astounding coincidences: Mexico had a nationwide earthquake safety drill today to mark the anniversary of the Sept 19, 2017 M 7.1 quake and the Sept 19, 1985 M 8.0 quake.
Note: "astounding" in a human perspective doesn't mean anything geophysically strange is up! Mexico is no stranger to large quakes (especially on the subduction zone), and the probability of date coincidences can be surprising, as in the Birthday Problem: en.wikipedia.org/wiki/Birthday_…
To have 50% odds on a triply-shared birthday (or quakeday) among randomly-distributed birthdays, you need a group of 87. For a group of 30 (~# of M>7 quakes on the Cocos subduction zone since the 1985 quake), the odds of a triply-shared date is ~3%. Higher than you might think!
People occasionally DM me the earthquake "prediction" charlatans they stumble upon on social media, and I've seen enough to do a little write-up.
Here it is: my Taxonomy of Quake Quacks!
🧵
Before we get started with the categories, a reminder: no one can meaningfully predict earthquakes before they happen. Everyone (scientists especially!) would love if useful, better-than-random prediction existed, but nothing yet has stood up to scientific scrutiny.
Here are my categories. They may not be completely exhaustive, and they can overlap in one individual, but I think they cover most of what I've seen:
How do earthquake “prediction” con artists make it LOOK like they have a good track record, even though they’re totally unscientific hoaxters?
Let a seismologist fill you in.
Thread:
First, to be abundantly clear: no one can usefully predict earthquakes before they happen. Not you, not your pet, not some guy on the internet. We’d all love if good predictions were possible (seismologists included!), but nothing yet has stood up to scientific rigor.
Why talk about this? With the recent swarm on the Brawley Seismic Zone, we (again) saw prediction charlatans try to prey on anxieties and peddle misinformation. That sucks, of course, but it’s also actually dangerous, because it can muddle important information from real experts.
It’s here: the lockdown seismology paper is out in @ScienceMagazine! Here’s a thread sharing how this paper came to be, an intro to what we found, and a note on why it’s interesting. science.sciencemag.org/content/early/…
Back in March, @seismotom posted this figure to @Seismologie_be of ambient seismic noise on a seismometer in Belgium, showing a decrease in noise power when their local lockdown went into effect:
Lots of seismologists (myself included) were intrigued when we saw it, so we each started processing data from our local areas, posting the results to Twitter, and discussing it all in the replies. It was social distancing seismic noise, and social media seismology!
Required reading for geoscientists in the U.S. (and recommended reading for anyone who loves the outdoors) relevant to recent events: "Black Faces, White Spaces" by Dr. Carolyn Finney, about the relationships between Black Americans, the outdoors, and environmental organizations.
The book discusses the history of Black relationships with the environment, the way that this history informs modern collective memory, Black representation in outdoors-focused media and organizations, and Black action for and exclusion from environmental causes.
One major point of the book is that many outdoors and environmental spaces have been and still are unfriendly and unsafe for Black people, as demonstrated by recent cases like Christian Cooper, leading to a disconnect in Black participation in and perception of the outdoors.
I just learned on the @USGS earthquake history page that the largest recorded quake on May 20th was a M7.2 in 1990 in South Sudan. Event page: earthquake.usgs.gov/earthquakes/ev…
Africa isn't the first to most minds when thinking of quake-prone areas, but it does get some! Short thread:
Here's a map of quakes with M>6.0 since 1980 in the @USGS catalog. As you might guess, most large quakes (~130 of the ~150 shown) occur on the major tectonic plate boundaries surrounding the continent.
The quakes that are actually on the continent tend to follow the East African Rift system, which is like an almost-plate-boundary that's slowly pulling apart the Nubian Plate and the Somalian Plate (minor plates that sometimes get lumped into one African Plate). @USGS diagram: