Nepal Aftershocks

There have been 26 major aftershocks as of 2pm EST (18Z), all along the mountain ranges to the west of the earthquake epicenter.  Some have been quite strong – two near the original quake were over m6.0.  These are causing additional damage, probably additional casualties, as well as panic and disrupting rescue efforts.  The initial impact estimate was close to $2 Billion; with each aftershock that number goes up, and is now pushing $2.5 Billion, with most of that in Nepal, but likely several hundred million in damage in neighboring India.

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Massive shallow earthquake in Nepal, nearly $2 Billion in impacts expected

There has been a massive 7.9, shallow earthquake in central Nepal, impacting areas of China and especially India as well:

Overall economic impact to Nepal will easily exceed $1 Billion dollars, and impacts in India may exceed $500 Million.  Here’s what the model spread looks like.  Best estimate is $1.8 Billion, with  much of the uncertainty is due to construction quality.  Some scary but plausible scenarios are in the $6 Billion range, but the majority of models place impacts around $2 Billion:


Update: To put this in to context, the GDP of Nepal is about 66 Billion, so this event will be about 2% of GDP.  Recent “bad” natural disasters impacting the US like Hurricanes Sandy and Katrina were in the $50 to $80 Billion range, but that is only 0.4 or 0.5 % of the US GDP.  This earthquake would be a $320 Billion disaster in the US – something we’ve never experienced.

Early death reports are in the 500 range, but I would expect the final numbers to be well into the thousands.

This is a very vulnerable area, where the Indian subcontinent is ramming into Asia and uplifting the Himalaya Mountains, and previous severe earthquakes near Kathmandu have been devastating.

Maysak and the Philippines

Maysak should make landfall Sunday morning Philippines time (this evening US time) as a moderate tropical storm with peak winds around 55kts (63 mph, 100kph).  Impacts look to be in the $30 to $40 million range – much, much less than the forecast indicated a few days ago.  Here is the wind swath forecast using the latest JTWC track/intensity and my Taru model.


Maysak: much weaker landfall, impact on Philippines forecast less than $150 Million


Very different impact forecast than yesterday, and yet another good example of the complexity of forecasting the impacts of natural hazards.  The landfall intensity has decreased from 85 knots to 65 knots – a 25% decrease in wind speed.  But the impact forecast dropped by nearly 90% to from over a Billion dollars to about $130 Million!  Why?  Because the amount of force the wind creates (the “dynamic pressure”) is related to the square of the wind speed, not the wind speed itself.  So the pressure from a 65 knot wind is only 58% of the pressure of an 85 knot wind.  But it’s a bit more complex than that, and damage relates to a number of complex factors that ends up being a higher power factor of the wind difference above a threshold.  So for a typical house, an 85kt wind might cause 16% damage, whereas a 65 knot wind would only cause 4% damage.  Another factor in this case is that the swath of damaging winds is smaller, and misses the densely populated areas near the Capital, Manila.  Put all that together, and while the track doesn’t look that different, and the winds are a bit less, the damage forecast is dramatically different.  Which is a good thing – the Philippines really doesn’t need another disaster given the last few years of Typhoons and earthquakes.

Maysak continues towards Philippines; Damage near $1 Billion still predicted

Maysak is not as intense as yesterday, but is still an impressive and powerful storm at 130kts/150mph/240kph:

Forecast track has been pretty steady to hit the northern Philippines island of Luzon in a bit over three days:

On this track, and using the JTWC forecast intensity at landfall of 85 knots, the storm could cause upwards of $1 Billion dollars in damage.  For perspective, that is about 0.3% of GDP, or the equivalent of a $40 Billion dollar storm hitting the US.  That is about the same damage as Hurricane Ike, which hit Texas in 2008, and is the third most expensive storm in US history.  The Philippines has been hit be several intense storms the last few years, such as Haiyan in 2013 and Bopha in 2012 – in fact they have had 6 disasters that, in GDP equivalents, would have been worse than Hurricane Andrew, just since 2010.  Bad Luck, or changing climate ?