Another strong earthquake in Puerto Rico (Sat, 11 Jan 2020)

Sadly another fairly strong and shallow earthquake has hit the southwest coast of Puerto Rico:

From satellite images this morning before sunrise, it looked like lights were back on along the north west coast as well as around Ponce that had been out since the 7th.  Early word is that power is back out again, and additional structure damage and collapse is likely despite this being a weaker event due to previous, unrepaired damage.  The cumulative impact of the series quakes and aftershocks (and likely aftershocks from this one)  are now estimated at over $3.5 Billion.  Hopefully this series is not a precursor to something bigger.  The region has had M7 and has the potential for even M8 earthquakes.

Please don’t forget about Puerto Rico in all the noise over Iran, Impeachment, and the political horse racing season … yes, it’s a vulnerable place for earthquakes as discussed previously, and of course is in hurricane alley, but that is no excuse for the human suffering being played out down there.

Background on ongoing earthquakes in Puerto Rico

What’s going on with Puerto Rico?  To start with, Puerto Rico is in a very active seismic region. The really short version is that the surface of the earth consists of seven large and a bunch of smaller “plates” – chunks of the earth’s crust that float on the molten mantle below.  These plates are pushed around by plumes of molten material from below. Imagine stuff floating on top of a boiling pot, only in very slow motion, plates only move on average an inch or so a year.  If you want to learn more, here’s the Wikipedia article plate tectonics. All those gigatons of rock moving around builds up a lot of energy, and where they bump up against one another or pull apart, you get mountains and/or oceans, as well as volcanoes, earthquakes, and other neat stuff.  The Greater Antilles (Cuba, Hispaniola – Haiti/Dominican Republic – and Puerto Rico) are in a double subduction zone.  What that means is the region is being “pushed up” as two plates are trying to dive under each other.  Here is a 3d diagram from a recent research paper on the region

The north side, the Puerto Rico Trench, is pretty well understood.  The round of earthquakes we have seen the last few weeks is probably more related to the Muertos Trough to the south, which is not as well understood.

So can we expect more earthquakes?  The short answer is of course yes, but that avoids the key question of “how bad” and “when.”  We just can’t answer that given our state of knowledge about this stuff.  For example, did this round of events dissipate energy along the faults on the Island, and will things calm down?  Or is it just transferring energy and strain into a locked part of a fault that will rupture with a much bigger event?  At this point, we just don’t know.

In any event, please don’t forget the people of Puerto Rico who are suffering from yet another natural disaster. Satellite images from this morning still show extensive power outages across the west and south side of island.  These are our friends, neighbors, and fellow countryman – this situation is unacceptable.

Puerto Rico Earthquakes (7 Jan 2020)

There have been multiple earthquakes along the south coast of Puerto Rico over the last 24 hours, the latest a shallow (10km deep) 6.4 magnitude at 3:24am this morning.  Power is out in many areas, and damage could be extensive in areas from Santa Isabel to Guanica, particularly around Ponce.  We won’t know for sure until the sun comes up and damage surveys can be conducted.

Here are some quick look maps.  Am working on a new integrated seismic damage estimation system, so these are pretty basic … economic impacts are likely to be in the high hundreds of millions to under two billion for both events combined.

Yesterday’s 5.8:

This morning’s 6.5:

Puerto Rico has been hit hard the last few years.  I hope this event and those hurt by it are not get overlooked in all the turmoil over Iran, Impeachment, etc.

Even larger quake in California 6 July 2019

A bit north of the July 4th quake, but much stronger, at 7.1.  Just how much stronger?  It released 11.2 times the energy of the 6.4 magnitude quake on July 4th.  You will see terms like “bigger” in the media, but that is a bit misleading.  The key variable is how much energy is released.  The “bigger” term is just a measure of the size (amplitude) of the seismic waves on the seismograph, which uses a logarithmic scale.  But it’s energy that causes damage. USGS has a nice explanation here.

Fortunately, both of these quakes happened in a lightly populated area of the state, near the China Lake Naval Weapons Station and the Ridgecrest/Indian Wells area.  Still, the economic impacts of this series are likely to be well over $1 Billion dollars, with the current estimate (8am ET Saturday Morning) ranging from $1.5 to $3.8 Billion and a current “best estimate” (based purely on the computer models, which do anticipate additional aftershocks) of around $2.6 Billion. This quake probably only added a few hundred million to the estimated impacts.  Note these numbers are total economic impact, which includes things like business disruption (like Disneyland having to shut down rides), road repairs, as well as the more typical physical damage like buildings and post-earthquake fires and damage to government facilities like China Lake.  Insured losses (which is the only thing insurance companies care about) are likely to be light, especially given the trend towards very high deductibles for earthquake insurance.  That means the consumer (you) get stuck with the bill … so be careful when people say things like “damage is light” because chances are it’s based on models or estimates used by insurance companies, and they don’t include it if it doesn’t exceed the deductible or isn’t insured by them (like roads or government buildings).  And of course there are real people living there .. even if not huge numbers like LA or Las Vegas … and they matter!

Earthquake in Southern California quick look estimate $1 to $3 Billion

Quick look economic impact estimate between $1 and $3 Billion, most likely $2.7 Billion … which isn’t really that much for the US, but still significant.  Low end is $700 Million, high end worst case model came in just over $3 Billion, based on data available as of 3pm ET Thursday 4 July.

AL14 (Future Michael), Earthquakes, and other stuff

Several big events over the last two weeks, especially the earthquake/tsunami in Indonesia and the earthquake in Haiti yesterday evening.  And more Pacific tropical stuff.  Have been swamped with research stuff and will try to catch up over the next day or two, but getting lots of queries about the storm off of Belize so will say a few words about that first.  Here’s the noon Sunday satellite view …

Other than gusty winds, for the Caribbean threat is mostly to the west end of Cuba as the storm makes its way out into the Gulf over the next day or so.  The 11am NHC Advisory package for Tropical Depression 14, which will likely reach tropical storm status and be named Michael this evening, has landfall on the Gulf coast of Florida sometime Wednesday.  For those of you who just can’t live without your daily dose of pasta, here’s a look at some of the major forecast model track guidance guidance NHC was taking in to account in creating this forecast.  Some show landfall as far west as Mobile Alabama, some as far east as the “Big Bend” area of Florida, near Steinhatchee.  The big dynamic models bring the storm in as a Hurricane, so if you are on the Gulf Coast pay attention. The overall impacts depend a lot on the track – one of those “duh” things meteorologists like to say.  The further west, the more likely effects will be confined to the coast near landfall, and the storm will degenerate over land.  Further east, especially for a “back door” type storm that makes landfall on the Gulf Coast, exits or skirts the coast of GA/SC/NC, it’s a more widespread problem. 

Just a brief rant (again, sigh) about showing track models maps, especially those sites who show all of the individual tracks as the haze of lines.  Lets look at that brown line on the map above in more detail. Here is JUST the GFS Ensemble model and the members of that ensemble.  So in simple terms the way this works is that the model is run a number of times (in this case 20) using “perturbed” (different) initial conditions based on the uncertainty in the storm position and characteristics, with an averaging program run to get the average track.  The individual runs are interesting for understanding the uncertainty of the forecast, but treating them as “equal probability” outcomes is misleading – and it’s just plain wrong to go ZOMG THE AP20 RUN SHOWS A DIRECT HIT ON SAVANNAH as if that is a stand alone forecast equal to something like HMON or especially the consensus track models (much less the human-assisted official NHC track).  So I’ll say it again: be sure your pasta is cooked by a real chief and chew well before swallowing it 😛

NHC is more or less splitting the difference (as does the consensus model blend) and takes the storm over Panama City.   Fortunately we’re not looking at a Florence/Harvey kind of “move just lnland and stall” scenarios, this looks to be the typical “landfall and move on” 24hr kind of event.  Here’s the impact swath based on the official NHC track forecast (which, as I often rant, is the only thing you should really worry about) …

Notice how broad the wind field gets after landfall, and the big swath of 40mph+ winds that are offshore.  This is typical for a storm that accelerates rapidly after landfall.  For those in Georgia and SC, don’t freak out over maps like this that show the storm as a tropical storm well inland.  First, as you can see here, the strongest storms will likely be well away form the center, and mostly confined right on the coast.  Second, NHC tends to overestimate the inland winds from an impact standpoint.  (said in a different way, while it is true there might be a small patch of winds of tropical storm force 24 hours after landfall, it isn’t likely to be as widespread as models and graphics based on their forecast show).  That’s fine for planning purposes, but don’t get too upset over it just yet.  Again, small changes in this track can produce big changes in impacts, so watch for the official watches and warnings.  A direct hit on the Panama City area by a Category 1 hurricane could be messy – current impact estimates are around $4.5 Billion, but it’s so early that number isn’t very reliable.

Large, but deep, m8.2 earthquake in the Pacific

There was an intense earthquake in the Pacific last night near Fiji.  It was rather deep, about 560km below the surface of the earth, and apparently did not cause any significant damage or create a tsunami.  Remember there are three major aspects to earthquake damage: intensity (magnitude), depth, and the surface soil characteristics.  The first two are the big factors; a 6.0 near the surface (10km deep) will cause much more damage than a 8.0 several hundred km deep even though the 8.0 releases a thousand times more energy!

Java Earthquake; Hurricane Hector and Hawai’i

A major earthquake hit the tourist areas of Java and Bali yesterday, leaving dozens if not hundreds dead, thousands homeless, and chaos in many areas.

Economic impacts are likely to be between $2 and $3 Billion dollars – major damage and a big hit for the local economy.  This is likely to be an ongoing disaster, and as usual one the US media will lose interest in once the tourists are evacuated.

Meanwhile in the central pacific, Hurricane Hector is on track to pass south of the big island of Hawai’i.  If it stays on track, while rain and gusty winds are possible not likely to cause much damage aside from the occasional tree down.  A rightward wobble could made things worse – and given the ongoing eruptions, folks there might be consulting the sages as to which gods they have offended …

Tropical Update, Saturday 2 June 2018

Only one actual system, in the South China Sea heading passing the west side of Hainan Island on Tuesday, then slowing down a lot and approaching the Guangxi coast by Thursday.  The Joint Typhoon Warning Center forecast has it becoming a tropical storm  by that time; on that track impacts are on the order of $25 Million, but a wobble or intensity increase makes that estimate pretty much useless at this point …

Elsewhere is quiet.  Might get something in the East Pacific (off Mexico) next week.  A few scattered earthquakes, all below magnitude 6.  The Kilauea volcano in Hawai’i is still active, with one fountain still spraying lava over 100 feet in the air, down from 260 feet a few days ago.  Think about how much power it takes to jet water a few hundred feet, much less hot molten rock …