Update May 29 13:19 UTC : Local reports are mentioning houses with cracks in Salva León de Higuey
Update 22:24 UTC : List of the most recent earthquakes closest to today’s epicenter. Interesting to see is that almost all of these earthquakes are very deep, this due to the movement of the Oceanic plate towards the south (she dives below the Caribbean plate). The tectonics of this Caribbean area are very complex with a number of sub-plates as well as dangerous transform faults, like the one who generated the cruel Haiti earthquake. Transform faults are resulting in a mainly horizontal movement which can generate a lot of damage to not properly build houses.
Update 22:24 UTC : Below the seismogram of this earthquake as recorded in Presa de Sabenta, Dominican Republic
Update 21:57 UTC : The main reason why this earthquake was felt in such a wide radius (Puerto Rico and Dominican Republic) is the depth of the hypocenter or breaking point. Although the radius is very wide, the concentrated shaking at the epicenter is luckily also a lot weaker. When this earthquake would have been shallower the risk on serious damage would have been a lot bigger.
Update 21:46 UTC : USGS has increased the Magnitude again to M5.8 at the same depth. Below the shaking intensities for the most important cities close to the epicenter.
Update 21:39 UTC : USGS has recalculated the Magnitude and has set it now to M5.7 at a depth of 91 km. USGS projects a max. Moderate shaking in the eastern part of the Dominican Republic and a weak shaking in Puerto Rico.
Update 21:35 UTC : The earthquake will surely NOT generate a tsunami.
Update 21:32 UTC : The preliminary earthquake Magnitude values are in between 5.3 and 5.8 at a depth of 100 km. This means that there is only a limited chance on serious damage. The deeper the hypocenter is, the less chance on damage.
Update : Below the Focal Mechanism or Beach Ball of this earthquake. It shows a clear compression
31km (19mi) ESE of Boca de Yuma, Dominican Republic
37km (23mi) S of Punta Cana, Dominican Republic
55km (34mi) SE of Salvaleon de Higuey, Dominican Republic
68km (42mi) ESE of La Romana, Dominican Republic
175km (109mi) E of Santo Domingo, Dominican Republic
Tropical Storm Isaac is pounding Haiti and the Dominican Republic with torrential rains that are causing extremely dangerous flooding and landslides. Isaac’s center passed over Haiti’s southwest peninsula early this morning, tracking about 50 miles west of the capital of Port-au-Prince. As the center pulled away to the northwest, Isaac’s heaviest thunderstorms moved ashore over Hispaniola near sunrise, and are now dumping heavy rains with rainfall rates approaching one inch per hour, according to recent microwave satellite estimates.Barahona on the south coast of the Dominican Republic had received 5.14″ of rain as of 8 am EDT this morning, and it is probable that some mountainous areas in Haiti and the Dominican Republic have already received up to 10″ of rain from Isaac. These rains will continue though much of the day, and have the potential to cause high loss of life in Hispaniola.
Figure 1. A river north of Port-au-Prince, Haiti in flood due to rains from Isaac. Image from Amélie Baron via Twitter.
Isaac built a partial eyewall last night as the storm approached Haiti, but passage over the rough mountains of Haiti has destroyed the inner core, and the surface center of the storm is now fully exposed to view on satellite images. Radar out of Guantanamo Bay, Cuba shows no sign of an organized center, but does reveal some very intense thunderstorms affecting Eastern Cuba, Western Haiti, and nearby islands. Latest data from the Air Force Hurricane Hunters confirm that Isaac has weakened; during their penetration to obtain their 7:08 am EDT center fix, the aircraft reported top surface winds of 55 mph with their SFMR instrument, top flight-level winds at 5,000 feet of 68 mph, and a pressure rise of 3 mb, to 998 mb. Infrared and visible satellite loops show that Isaac remains a large and well-organized storm, though it lacks an inner core. An analysis of upper level winds from the University of Wisconsin CIMSS shows that upper-level outflow is still good to the north, but is lacking elsewhere. An impressive large multi-day satellite animation of Isaac is available from the Navy Research Lab.
Figure 2. Rainfall rates estimated by the NOAA F-17 polar orbiting satellite at 6:21 am EDT August 25, 2012. Rainfall rates of 1 inch per hour (orange colors) were occurring in a large area to the south of Hispaniola, and these heavy rains have now moved onshore. Image credit: Navy Research Laboratory.
Latest model runs for Isaac
The latest set of 0Z and 06Z (8 pm and 2 am EDT) model runs are similar in spread to the previous set of runs. Our two best models, the GFS and ECMWF, are virtually on top of each other, with a landfall location in the Florida Panhandle between Fort Walton Beach and Panama City. It is likely that the trough of low pressure pulling Isaac to the north will not be strong enough to pull Isaac all the way to the northeast and out to sea, and Isaac has the potential to drop torrential rains capable of causing serious flooding over the Southeast U.S. The latest 8-day precipitation forecast from the GFS model (Figure 3) calls for 10 – 15 inches of rain over portions of Georgia and South Carolina from Isaac. The ECMWF model, however, predicts that a ridge of high pressure will build in and force Isaac to the west after landfall, resulting in a slow motion across the Tennessee Valley into Arkansas by Friday. Arkansas is experiencing its worst drought in over 50 years, so the rains would be welcome there.
Figure 3. Predicted precipitation for the 8-day period from 2 am Saturday August 25 to 2 am Sunday September 2, from the 2 am EDT August 25 run of the GFS model. This model is predicting a wide swath of 5 – 10 inches of rain (orange colors) will affect portions of Cuba, Florida, the Bahamas, and the Southeast U.S. Image credit: NOAA/NCEP.
Intensity forecast for Isaac
Isaac survived passage over Hispaniola relatively intact. It’s large size aided this, and this will also help it survive passage over Cuba today and Sunday. By the time Isaac pops off the coast of Cuba into the Florida Straits on Sunday, it will likely be a 50 mph tropical storm with a large, intact circulation. Isaac will be over very warm waters of 31°C (88°F) in the Florida Straits, wind shear will be light to moderate, and the upper-level wind pattern will feature an upper-level anticyclone over the storm, aiding its upper-level outflow. As I discussed in my previous post, Crossing Hispaniola and Cuba: a history, there have been five storms since 1900 with an intensity similar to Isaac, which crossed over both Haiti and Cuba, then emerged into the Florida Straits. These five storms strengthened by 5 – 20 mph in their first 24 hours after coming off the coast of Cuba. Given the relatively intact structure of Isaac so far, and the favorable conditions for intensification, I expect Isaac will intensify by 15 – 20 mph in 24 hours once the center moves off of the north coast of Cuba. If Isaac spends a full two days over water after passing the Florida Keys, it is possible that it will have enough time to develop a full eyewall and undergo rapid intensification into a Category 2 or 3 hurricane. The latest 06Z (2 am EDT) run of the GFDL model is calling for Isaac to intensify to Category 2 strength, then weaken to Category 1 at landfall in Mississippi on Tuesday. The 06Z HWRF run is calling for landfall in the Florida Panhandle near Fort Walton Beach as a borderline Category 2 or 3 hurricane. The 5 am EDT NHC wind probability forecast gave Isaac a 19% chance of becoming a Category 2 or stronger hurricane in the Gulf. I expect these odds are too low, and that Isaac has a 40% chance of becoming a Category 2 or stronger hurricane in the Northern Gulf of Mexico. I doubt the storm has much of a chance of hitting Category 4 or 5 status, though. While the surface waters in the Gulf of Mexico are very warm, near 30 – 31°C, the total heat content of these waters is unusually low for this time of year. We got lucky with the Gulf of Mexico Loop Current this summer, as it did not shed a big warm eddy during the height of hurricane season, like happened in 2005 (I discuss this in my Gulf of Mexico Loop Current Tutorial.) Without the type of super-high heat energy we had in 2005 in the Gulf of Mexico, Category 4 and 5 hurricanes in the Gulf of Mexico in 2012 will have difficulty forming.
Invest 97L off the coast of Africa
A tropical wave (Invest 97L) is located about 350 miles west-southwest of the Cape Verde Islands off the coast of Africa. The storm has a modest amount of spin and heavy thunderstorms, and is under moderate wind shear. In their 8 am EDT Tropical Weather Outlook, NHC gave 97L a 30% chance of developing by Monday morning. The 8 am EDT SHIPS model forecast predicts moderate shear for the next 5 days over 97L, so some development is possible if 97L can fend off the dry air to its north. None of the reliable models foresee that 97L will be a threat to the Lesser Antilles Islands. However, both the GFS and ECMWF models predict that a tropical wave that has not yet emerged from the coast of Africa may develop next week, and potentially take a more westward track towards the Lesser Antilles.
(As you know, the Dominican Republic shares an island with Haiti. My concern here is the possibility of another quake related to this one which could potentially affect Haiti also, if not the whole island. This is a land of great poverty and want. Even small natural disasters are magnified under such conditions, in terms of the effect on people there.)
Shallow earthquake in the southern part of the Dominican Republic
11:28 UTC : The Dominican Republic Civil Defense has alerted all of his services minutes after the quake occurred but at the time of writing this update, NO damage or injuries have been reported. Authorities in the direct epicenter area are currently inspecting buildings and public works to assess the situation.
11:04 UTC – Rock slides have been reported along the road from Azua to San Juan. Drivers are warned to be careful in driving this road.
11:02 UTC – The epicenter has been located 17 km South-East of Ocoa. Following the local media who are referring the the Dominican seismological agency UASD, the depth of the hypocenter was at 33 km and the magnitude was measures as 5.2. Both USGS and EMSC have reported a magnitude of 5.3 at a depth of 10 km. 33 km or 10 km makes a world of difference towards damaging capability.
– As early stated in this report, the earthquake has been felt almost all over the country but will have been felt also in neighboring Haiti !
– A lot of people are downloading our QuakeSOS iPhone application, but so far people are only testing and sending SAFE alerts.
– reports from the Dominican Republic are talking about people leaving their houses in panic (normal with such a magnitude)
– Maximum recorded (reported) MMI seems to be V = moderate shaking. Moderate shaking damage can be cracks in walls at max., but we will have to wait for a few more hours to be certain that no additional damage has been inflicted.
– The area has a lot of hills (see image)
– Closest villages to the epicenter (errors are possible within a radius of 16 km) : La Palma, Calderon, Hatillo, Agua, Galeon and Bani
– EMSC reports the same values than USGS (5.3 @ 10 km)
– The earthquake occurred during the early morning hours 05:35 AM !, when almost everybody was still sleeping
– the shallow hypocenter (focal depth) makes this earthquake moderately dangerous within a radius of 20 km.
Most important Earthquake Data:
Magnitude : 5.3
UTC Time : Thursday, January 05, 2012 at 09:35:29 UTC
Local time at epicenter : Thursday, January 05, 2012 at 05:35:29 AM at epicenter
Depth (Hypocenter) : 10 km
17 km (10 miles) SSE (149°) from Ocoa, Peravia, Dominican Republic 33 km (20 miles) W (270°) from San Cristóbal, San Cristóbal, Dominican Republic 50 km (31 miles) W (260°) from SANTO DOMINGO, Dominican Republic
for more information and updates, go to: http://earthquake-report.com/2012/01/05/shallow-earthquake-in-the-southern-part-of-the-dominican-republic/
As of 2AM EDT, Hurricane Irene was located at 21.3N, 72.6W, 400 miles southeast of Nassau. It was moving west-northwest at 9 mph with maximum sustained winds of 100 mph, making it a Category 2 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 966 mb. Hurricane warnings have been issued for all of the Bahamas and the Turks and Caicos Islands. Tropical storm warnings are in effect for Haiti from Le Mole St. Nicholas to the Dominican Republic border.
Figure 1 shows that Irene has a large eye visible in infrared imagery, (26 miles across accoring to a report from the Hurricane Hunters at 130AM) with well-defined outflow cirrus bands. Tuesday evening, TRMM, NASA’s tropical research satellite, flew directly overhead Irene, getting a radar scan of the storm using it’s downward pointing radar, shown in Figure 2. It is immediately apparent that Irene has well-developed bands of rain showers, with strong storms present in the eyewall.
Figure 1 IR satellite view of Irene taken at 113AM EDT, August 23, 2011