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Jackie Caplan-Auerbach 🇺🇦 🌻 Profile picture
Jackie Caplan-Auerbach 🇺🇦 🌻
@geophysichick
Seismologist, volcanologist, professor, and hazards junkie. Soapbox stander. Opinions are my own but I'm happy to share. She/her.
2 subscribers
Dec 8, 2022 • 18 tweets • 2 min read
I allowed my students two options for extra credit on their geophysics final exams this year: (1) write a haiku about geophysics or (2) explain what equation you would like tattooed to you. A selection of awesome answers follows: "Embryonic stretch
Juvenile thins into birth
Suturing unites"
Sep 30, 2021 • 19 tweets • 5 min read
In a previous tweet I noted how nice it is when Kilauea's eruptions don't negatively impact communities. Several responses suggest that people think that this is unusual and that volcanoes are wild and unpredictable beasts. Let's talk about that--about Kilauea in particular. Kilauea is most active volcano in HI, and among the most active in the world. It is one of 5 volcanoes that comprise the Big Island. Those volcanoes, and the likelihood of lava flow on their flanks, are shown below.
Jul 8, 2021 • 10 tweets • 2 min read
Are you reading Tweets about "phantom quakes" associated with the recent M5.9 in California? Wondering what a phantom quake is? Wondering why a quake vanished from the USGS list? Read on, friends! When an earthquake occurs, the seismic waves it generates are recorded by seismometers. We use the time that the waves arrive at different locations to calculate the hypocenter (location and depth) of the quake.
Oct 28, 2020 • 20 tweets • 6 min read
I recently found myself wondering what readers of Fox News are seeing about COVID-19, since I never see the kind of info there that I see on the NYT and WaPo (e.g. trends, numbers of infections). Thought I'd check out their website.

Come with me on a wild ride: Today's front page on @FoxNews has a ton of articles about the election, Hunter Biden, and about Big Tech (with a connection to Hunter Biden). If you scroll way down, you find two articles related to coronavirus. Both are there to scare you about things unrelated to health.
May 25, 2020 • 20 tweets • 4 min read
Yesterday was the 60th anniversary of the largest earthquake ever recorded, the 1960 Valdiva (Chile) M9.5. On this occasion I want to try to explain just how REALLY REALLY BIG big earthquakes are. Check out the figure below, and buckle up. The blue line in this figure shows the total amount of energy (well, seismic moment, but these are similar so we're going with it), released by earthquakes between 1900 and 2020. The figure shows cumulative energy--total released over time--which is why it constantly increases.
Jan 27, 2020 • 21 tweets • 5 min read
Today is the 320th anniversary of the last M9 earthquake to hit the Pacific NW. In honor of this event, my family has designated January 26 as the day that we update our earthquake kit each year. This thread shows a bit of what that looks like. First, let me be honest: I'm sure there's much more I could do, and this kit may not be enough. But it's a start and we improve it each year, so I'm good with that approach.
Dec 17, 2019 • 14 tweets • 7 min read
Flew home from #AGU19 today, and OH MY LORD, THE VIEWS. This is why we have window seats!

Be forewarned: a data dump of aerial volcanic goodness follows in this thread.

#AlwaysAWindowSeat #RaiseTheShades I few out of San Jose, so started with some nice views of the south bay and the Hayward fault.
Nov 29, 2019 • 17 tweets • 5 min read
Fun idea by @GeologyTime, but this tweet triggered a few of my Earth structure pet peeves. So I made my own version. The following thread explains...

The key issue that is different between the two versions is the common misconception that tectonic plates are made of crust. The original figure shows oceanic crust (blue) subducting into mantle (grey).
Jun 25, 2019 • 23 tweets • 5 min read
A Seismic Rant, by Geophysichick:

Rather annoyed, as I prepare my class on seismic waves for tomorrow. Nearly every website I find has a subtle but maddening error in how they discuss the speed of seismic waves. [A rant, but hopefully an educational rant, follows] For the most part, seismic waves move faster in denser materials. We see this as waves propagate into the deep mantle (they go faster!) and we see this when we compare how fast waves move in different types of rock (e.g. v = 6 km/s in basalt but 3 km/s in sandstone).
Apr 6, 2019 • 21 tweets • 5 min read
Gonna do a quick thing on earthquake magnitude here on #SeismogramSaturday. There's a lot to say, so this is just a small part. I'll chime in more about magnitude in later weeks, so keep watching this space.

Meantime, here's today's lesson: Magnitude is a measure of the raw size of the earthquake. It doesn't relate to how strong it felt or how much damage it did, because those things depend on factors like distance from the quake and the quality of infrastructure.
Mar 16, 2019 • 13 tweets • 5 min read
I was appropriately beaten to the punch by @earthquakeguy for this #seismogramsaturday, and he's much more of an expert on this topic than I, so please look at his post first. I'll add a few of my own figures below. Today we're talking about the tremor pulses that go hand-in-hand with slow slip during Episodic Tremor and Slip (ETS) events. These are fascinating events in subduction zones that are well described here: earthquakescanada.nrcan.gc.ca/pprs-pprp/pubs…
Mar 9, 2019 • 23 tweets • 6 min read
Today, #SeismogramSaturday is actually #SpectrogramSaturday. I'm going to talk about another way that seismologists might look at seismic data. The key background information here is that earthquake waves, like all waves, have a quality called "frequency", which describes how many times the wave oscillates per second (a unit called Hertz, or Hz).
Mar 2, 2019 • 15 tweets • 4 min read
Today's #SeismogramSaturday is devoted to my favorite category of earthquakes--volcanic quakes. These are events that occur within volcanoes, due to a variety of causes. We'll discuss three types of volcano quakes today. In general, all quakes occur when some type of stress causes rock to break or slip. In tectonic environments, the driving force is plate tectonics. In volcanoes, the forces are different--usually magma, but also fluids or the weight of the mountain itself.
Feb 23, 2019 • 24 tweets • 6 min read
Today, on #SeismogramSaturday: what are all those strangely-named seismic phases described in seismograms from distant earthquakes? And what do they tell us about Earth’s interior? In the past couple of weeks we’ve discussed body waves (P and S waves, which move through the body of the Earth) and surface waves (Love and Rayleigh which, unsurprisingly, only travel across Earth’s surface).
Feb 16, 2019 • 21 tweets • 4 min read
Okay, #SeismoTwitter, it's (almost) #SeismogramSaturday! I'll be offline for most of Saturday, so I'm posting a little early. Here's today's seismogram! Today, we have show shaking caused by the M9.0 Tohoku earthquake on March 11, 2011. This figure shows shaking at a station in North Dakota (caused by a quake in Japan!).
Feb 10, 2019 • 12 tweets • 3 min read
Hey #SeismoTwitter! I propose that we do #SeismogramSaturday, to teach about the world of our wiggles. Feel free to pick your favorite (or least favorite) seismogram to tell us about. We'll do it next week too.

I'll start. This is a normal little quake. Info follows: First, a seismogram literally shows us how the ground shook when seismic waves reached the seismometer. The vertical axis is a proxy for this (I'll explain the units later).