this morning, around noon-ish, I heard a loud BANG and felt a small shudder outside my work area, at first, i thought someone ran into the building, but when I checked, there was no one out there, so then I thought since our next-door neigbors (the same jerks that were jackhammering up their floor a few months ago) are moving out, it wasn’t them, so I jokingly remarked to my co-workers “must have been an earthquake”
it was!
one of my co-workers was off on an onsite call, and went to register his car at the Portsmouth town hall, apparently the subject there was todays small earthquake
nothing on the news yet, not sure what it measured on the Richter scale, but it was small
lets see, we had snow squalls and an earthquake this morning, what’s next…
2.4? And you felt it? Around here, that’s just someone sitting down hard in a chair two rooms over.
It’s funny to look at the USGS national map and see one tiny mark way off on the east coast, while the west coast is covered in marks. (The color refers to how long ago, rather than strength)
You can joke about it. I mean, compared to the hazards you are used to, it is a laughable event.
But it underscores what I understand to be a real risk: earthquakes can happen anywhere. They’re usually associated with a fault, but even that’s not an iron-clad rule. And compared to SF, or any west coast city, the east coast is a tectonic disaster waiting to happen.
I won’t be surprised to hear that there are some real costs in terms of homeowner or business insurance claims because of this - in a large part because unlike the west coast the east coast doesn’t build with an eye towards tectonic events. The was I undestand it, it is very unlikely that there’s going to be a large magnitude quake in the Northeast anytime in the near geologic future. But there’s no guarantee that there won’t be.
And I shudder to think what might happen in places like Manhattan, or worse - Boston’s Back Bay, which is built on reclaimed land - when one happens.
Also, as I understand it, because there are fewer faults, the shockwaves from an earthquake can travel farther. The less fractured rock transmits the shock more efficiently. So, a big quake like the 8 point New Madrid Earthquake hits harder and farther in normally stable regions, on the occasions that one does happen.
an arch. firm had a client that complained about the cost of the earthquake code. “what do we need that for??? we are in pennsylvania!” that was friday.
sat. morning around 5am a wee earthquake hit (3ish on the scale, enough to wake you up and go “huh”). the building was in the putting up the steel phase. the earthquake was centered in the town.
monday morning the project arch. was hopping around the office, shouting: “vindication!!!” when he went to the site later that day, inspections found that the steel had held and wasn’t out of position. construction could continue.
and that’s why you pay for the extra steel in the code. and don’t dis mother nature.
that was how a seismologist described it to me back when indiana had it’s most recent big one in the 80s. i was a newspaper reporter then, so of course we shifted into overdrive and about drove Golden, CO (USGS headquarters or something. i’ve since forgotten) nuts with questions.
according to Golden, places like LA have all that fractured rock inderneath, like **der trihs ** mentioned, which tends to interfer with how well a quake shakes up the area.
but here in the midwest, we sit on lots and lots of nice, crumbly farmland - perfect for transmitting the waves, and resulting in even more damage than the size of the original quake would normally warrant. the quake in 1811 rang churchbells in philly and made the mississippi river run backward for two days. a sobering thought, indeed.
that’s why another quake anywhere in the ballpark of the size of the 1811-12 shake will probably destroy a serious chunk of the central united states infrastructure. and i live about 350 miles from what is considered to be ground zero - well within what could be considered the danger zone.
