Storm surges are amazing. I've never seen one happen but I've seen the aftermath. A video has surfaced of a storm surge hitting Hernani in Eastern Samar, shot from the second floor of a house that was a few hundred meters from the coast.
A storm surge is a mound of water caused by the wind of a hurricane (or other storm) pushing the water ahead of it, and further heightened by the low pressure system of the storm. In a given major storm there can be many, but there seems to be one big one most of the time. If the surge happens at high tide it is worse. If it happens at spring high tide in a high latitude (like New York or Boston, or Bourne) it can be way worse.
Also, the surge can be significantly enhanced if it forms in open water and pushes into an embayment or restriction of any kind, which is often the case where human settlements occur, as we tend to settle on estuaries or harbors.
Anyway, here's the video:
Impressed? On one hand you should be. That's a lot of power coming in from the sea. On the other hand, you shouldn't be. This storm surge left quite a bit standing. It was shot from a house that survived, obviously. As impressed as you might be with this storm surge, it was probably not the biggest one that hit in the Philippines during Haiyan. The people shooting those videos would not have lived to pass them on to us.
I was researching this this morning looking for historical evidence of one particular surge. I did find that the biggest in recorded history were in the five meter neighborhood. Those were once in a millenium storms. That one looked like it was approaching four.
On the other hand, the ski season opened early at Whistler, so climate change is a scam.
I did find that the biggest in recorded history were in the five meter neighborhood.
Five meters is nowhere near a record. The record for the Atlantic basin is 8.47 meters (assuming I've done the units conversion right) at Pass Christian during Hurricane Katrina. The topography of the Mississippi coast region makes it particularly vulnerable to storm surge; the previous record Atlantic storm surge, from Hurricane Camille, also occurred there (6.95 m). I've seen reports of a storm surge of more than 13 m from a cyclone hitting Australia, but don't know how reliable the reports are.
are you ading tides and added surge or keeping the surge separate
I think other than the very high tide effects in some areas (a one foot surge at the right time in the Bay of Fundy = a 41 foot surge!) the biggest effect is usually going to be the shape of the coastline. Also, the tide gages are not accurate reflections of local conditions. My SIL's ceiling, which was lower than Bob's surge, was far above the recorded surge level, but she happend to not be living on the tide gauge, which was located on a nearby river outlet.
One report for Haiyan would have had the surge at 12 meters in one location.
Related: The surge is generally measured where there is already water ... at a tide guage, but the water climbs up on to land. How do you count 10 feet of water sitting on top of a 10 foot asl elevation? Is that 20 ft? (that would be the operative number if looking at a top map and wondering if your house will be flooded) or is that a 10 foot surge?
I think the numbers I quoted are in addition to the tide, but tides along the US Gulf coast are relatively small (typically a couple of feet between low and high tide), so that would not make as big a difference as it would in New England or the Bay of Fundy. And yes, you would add land elevation to water height to compute storm surge at your location--I've seen eyewitness accounts of a location 10 feet above sea level that got 17 feet of water from Katrina's storm surge.
The shape of the coastline is a major factor in storm surge height, but it also matters how steeply the land rises as you go from continental shelf to coastal plain. Shallow slopes, like the Gulf of Mexico, favor higher storm surges compared to mountainous near-shore terrain in places like the Antilles (I'm not sure of the detailed physics, but I think it's a similar gradual funneling effect to what bays provide). New York is in one of the especially vulnerable spots: simulations of a Category 4 hurricane approaching on a track similar to Sandy's produce a surge of more than 10 m in New York Harbor.
The storm surge height does not include battering waves riding on top of it. Twelve meters of storm surge in the Philippines sounds high to me, but 12 m of storm surge plus battering waves is quite plausible.
It appears that 5.3 m is the highest recorded for Haiyan. Locally the max was probably higher in places.
You may be interested in having a read of my article "SpotlightON – The Philippines, BBC “Question Time” and CACC" which includes a mention of an equally horrendous typhoon in th esmae area which killed around 7000 - back in October 1897!
Best regards, Pete Ridley
And since there was a typhoon in 1897 global warming is a hoax!!!
The official death toll in that storm was not even close to 7000. More like 1500. Do you have a link for your article, sounds interesting!
Pedro Ribera, Ricardo Garcia-Herrera and Luis Gimeno (July 2008). "Historical deadly typhoons in the Philippines". Weather (Royal Meteorological Society) 63 (7): 196.
3 weeks before Haiyan, we were the epicenter of a Typhoon, with high tide, unrelenting rain and subsequent dam release, we had flooding to 4.5 feet in the house, and much more fortunate than most, though didn't seem like it then but compared to Tacloban City unquestionably.
But, regardless of surge with or without tides, when its chest high in your living room its a lousy day.
We just yesterday found out our family in Tacloban are okay, but began a project using facial recognition to help identify victims dead or alive after disasters, where is my family on indiegogo.
Bottom line though is I think we will have more mega disasters than ever, they seem to hit faster and stronger. Next few years I'm sure Haiyan will be out gunned.