Friday, May 15, 2015

PLANETARY TREMORS: Strong 4.6 Earthquake Rocks Central New Zealand! [MAPS + TECTONIC SUMMARY]

USGS earthquake location map.

May 15, 2015 - NEW ZEALAND
- A strong earthquake measuring 4.6 has hit Marlborough.

GeoNet is reporting it was located 5km south east of Seddon, south of Blenheim followed by a 3.3 located 30km east of Turangi.

The quakes hit shortly after 5.30pm.

Chris Sutherland was enjoying a pint in Paddy Barry's pub in Blenheim when he felt the jolts.

"I was sitting on a bar stool and it rocked a bit and the drinks on the table moved a little bit. Luckily my drink wasn't spilled. If it had I would have licked it off the table."

Pam Tawhara said it knocked over her cuppa and she had to hold onto her desk and computer.

"It took years off my life."

Jodi Cane from Seddon said it "felt like a train coming though our lounge, quite a shake."

Robyn Thomson said her car parked in Springlands in Blenheim rocked as a result of the jolts.


USGS shakemap intensity.

Wendy Gibson described it as a "rumbling jolt".

A St John spokesman said there were no reports of injuries or damage.

A Marlborough District Council spokeswoman said it was "no biggie" and there had been no reports of buildings damaged.

On Twitter people reported feeling swaying buildings but no damage or injuries.
That wasn't fun. #eqnz
— Chelsea McLaughlin (@chelseamc5) May 15, 2015
That was an #eqnz right as an enormous gust came past. THANKS FOR THAT I WASN'T USING MY HEART OR ANYTHING.
— Jess B (@jesscabah) May 15, 2015
Floods and earthquake in @Wellington_NZ - please give the poor city a break! #eqnz
— Tash Pieterse (@TashTasticNZ) May 15, 2015
Trying to work and building is still swaying from that jolt. I think it's time to bail and go to Muay Thai #eqnz
— Kim Anderson (@_kim_anderson) May 15, 2015

- Stuff.




Tectonic Summary - Seismotectonics of the Eastern Margin of the Australia Plate

The eastern margin of the Australia plate is one of the most sesimically active areas of the world due to high rates of convergence between the Australia and Pacific plates. In the region of New Zealand, the 3000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand.

Since 1900 there have been 15 M7.5+ earthquakes recorded near New Zealand. Nine of these, and the four largest, occurred along or near the Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting intraplate deformation. The largest recorded earthquake in New Zealand itself was the 1931 M7.8 Hawke's Bay earthquake, which killed 256 people. The last M7.5+ earthquake along the Alpine Fault was 170 years ago; studies of the faults' strain accumulation suggest that similar events are likely to occur again.

North of New Zealand, the Australia-Pacific boundary stretches east of Tonga and Fiji to 250 km south of Samoa. For 2,200 km the trench is approximately linear, and includes two segments where old (Greater than 120 Myr) Pacific oceanic lithosphere rapidly subducts westward (Kermadec and Tonga). At the northern end of the Tonga trench, the boundary curves sharply westward and changes along a 700 km-long segment from trench-normal subduction, to oblique subduction, to a left lateral transform-like structure.


USGS plate tectonics for the region.

Australia-Pacific convergence rates increase northward from 60 mm/yr at the southern Kermadec trench to 90 mm/yr at the northern Tonga trench; however, significant back arc extension (or equivalently, slab rollback) causes the consumption rate of subducting Pacific lithosphere to be much faster. The spreading rate in the Havre trough, west of the Kermadec trench, increases northward from 8 to 20 mm/yr. The southern tip of this spreading center is propagating into the North Island of New Zealand, rifting it apart. In the southern Lau Basin, west of the Tonga trench, the spreading rate increases northward from 60 to 90 mm/yr, and in the northern Lau Basin, multiple spreading centers result in an extension rate as high as 160 mm/yr. The overall subduction velocity of the Pacific plate is the vector sum of Australia-Pacific velocity and back arc spreading velocity: thus it increases northward along the Kermadec trench from 70 to 100 mm/yr, and along the Tonga trench from 150 to 240 mm/yr.

The Kermadec-Tonga subduction zone generates many large earthquakes on the interface between the descending Pacific and overriding Australia plates, within the two plates themselves and, less frequently, near the outer rise of the Pacific plate east of the trench. Since 1900, 40 M7.5+ earthquakes have been recorded, mostly north of 30°S. However, it is unclear whether any of the few historic M8+ events that have occurred close to the plate boundary were underthrusting events on the plate interface, or were intraplate earthquakes. On September 29, 2009, one of the largest normal fault (outer rise) earthquakes ever recorded (M8.1) occurred south of Samoa, 40 km east of the Tonga trench, generating a tsunami that killed at least 180 people.

Across the North Fiji Basin and to the west of the Vanuatu Islands, the Australia plate again subducts eastwards beneath the Pacific, at the North New Hebrides trench. At the southern end of this trench, east of the Loyalty Islands, the plate boundary curves east into an oceanic transform-like structure analogous to the one north of Tonga.

Australia-Pacific convergence rates increase northward from 80 to 90 mm/yr along the North New Hebrides trench, but the Australia plate consumption rate is increased by extension in the back arc and in the North Fiji Basin. Back arc spreading occurs at a rate of 50 mm/yr along most of the subduction zone, except near ~15°S, where the D'Entrecasteaux ridge intersects the trench and causes localized compression of 50 mm/yr in the back arc. Therefore, the Australia plate subduction velocity ranges from 120 mm/yr at the southern end of the North New Hebrides trench, to 40 mm/yr at the D'Entrecasteaux ridge-trench intersection, to 170 mm/yr at the northern end of the trench.

Large earthquakes are common along the North New Hebrides trench and have mechanisms associated with subduction tectonics, though occasional strike slip earthquakes occur near the subduction of the D'Entrecasteaux ridge. Within the subduction zone 34 M7.5+ earthquakes have been recorded since 1900. On October 7, 2009, a large interplate thrust fault earthquake (M7.6) in the northern North New Hebrides subduction zone was followed 15 minutes later by an even larger interplate event (M7.8) 60 km to the north. It is likely that the first event triggered the second of the so-called earthquake "doublet".

More information on regional seismicity and tectonics

- USGS.





GLOBAL VOLCANISM: Seismic Unrest - Restless Activity Beneath Hawaii's Mauna Loa Volcano!

Mauna Loa erupting
May 15, 2015 - HAWAII - The recent high lava lake levels at Kīlauea Volcano have caught the attention of visitors and kama‘aina alike. But we shouldn’t forget that unrest at Mauna Loa continues.

Ongoing inflation in the upper Southwest Rift Zone and summit areas of Mauna Loa suggests that magma continues to rise into the volcano. The current rate and pattern of deformation are similar to the most recent episode of rapid inflation on Mauna Loa in 2004-2005. Earthquakes have also been occurring at elevated rates, particularly around the areas of inflation in the upper Southwest Rift Zone and summit.


WATCH: Time-lapse multi-image movie of Mokuʻāweoweo Caldera from the Northwest Rim on Mauna Loa. May 7-14, 2015. Images courtesy of USGS/HVO.




Throughout its history, the USGS Hawaiian Volcano Observatory (HVO) has taken advantage of advances in technology to better monitor volcanoes and earthquakes. Computers have become faster, methods of transmitting information have improved, and instrumentation has become smaller and more energy efficient. All these advances have been utilized to create an improved geophysical network that better supports HVO’s monitoring and science efforts.

In 2009, the American Recovery and Reinvestment Act (ARRA) enabled a major upgrade to HVO’s monitoring networks on Mauna Loa and Kīlauea, including a conversion to digital telemetry, additional monitoring sites, and improved instrumentation. These enhanced networks can now detect earlier stages of unrest, and the resulting data enables more sophisticated analyses of volcanic processes than were previously possible.

Since the two most recent eruptions of Mauna Loa in 1975 and 1984, HVO started using GPS, broadband seismometers, and several types of analyses that were not possible with previous geophysical networks and computers. Certainly, these new data streams and analysis techniques have led to an improved understanding of Mauna Loa and its magma storage system.

Scientists often try to compare previous periods of unrest, such as those in 1975 and 1984, to current unrest to gain perspective on and understanding of what might happen next. With our improved ability to detect smaller and smaller earthquakes and deformation, it is important to keep in mind that signals being recorded now might not have been detectable in past years. This leads to some interesting questions that we’re trying to answer.

Were the small earthquakes that we can now record present during previous periods of unrest on Mauna Loa? If so, what was their pattern?


WATCH: Hawaii Volcano Eruption Update - May 15, 2015.



With entirely new techniques available, such as GPS and interferometric radar (InSAR), we can measure the deformation of wide areas on the volcano, which allows us to detect a large, inflating magma reservoir beneath Mauna Loa that previously could not have been detected. But, was this same reservoir active before previous eruptions?

Continuously recording GPS receivers measure episodes of hugely varying rates of inflation interspersed with times of no inflation, which might indicate fluctuations in magma supply to Mauna Loa’s shallow storage system. Did these fluctuations occur in the past? The comparison of current and past activity is not as trivial as one might think.

And finally, what will be the outcome of Mauna Loa’s current unrest? Scientists cannot be sure at this point.

Seismic unrest is currently much less energetic than it was before the 1975 and 1984 eruptions. Several episodes of increased inflation since 1984 slowed and stopped without eruption. Each of these episodes, however, resulted in greater pressurization of the shallow storage system within Mauna Loa. Unfortunately, we do not yet completely understand exactly how much pressure is involved, or how much internal pressure the overlying rock can bear before it breaks and allows magma to move toward the surface.

Our knowledge and characterization of volcanic systems constantly evolves as improved geophysical networks lead to new scientific discoveries. But before scientists can clearly distinguish between episodes of inflation and elevated earthquake activity that accompany only the intrusion of magma (with no eruption) and those that actually lead to an eruption, there is still much work to be done.

So, HVO scientists continue their diligent efforts to fully understand the processes at work beneath Mauna Loa and to monitor the volcano’s restless activity. If any significant changes are observed, HVO will issue public notifications through media releases and our website updates (hvo.wr.usgs.gov/activity/mauna…) - Hawaii 24/7.




 

INFRASTRUCTURE COLLAPSE: Plane Crashes In Malheur County, Juntura, Oregon - One Person Killed!

Juntura plane crash. (Photo: Malheur County Sheriff's Office)

May 15, 2015 - OREGON, UNITED STATES
- A well-known ranch owner was killed Thursday morning when the small aircraft he was using to herd cattle crashed in Malheur County.

The crash happened at about 10:35 a.m. in Juntura, a rural community about 60 miles southwest of Vale.

Michael Bentz, 51, was using a 1979 Bellanca plane to move cattle with help from cowboys on the ground when his aircraft hit a power line, Malheur County Sheriff Brian Wolfe said.


Malheur County plane crash. (Photo: Malheur County Sheriff's Office)

The plane plummeted to the ground, landing on its top and killing Bentz, the sole occupant.

Wolfe said Bentz is the brother of Oregon State Rep. Cliff Bentz, R-Ontario, and former Malheur County Sheriff Andrew Bentz.

Using small aircraft to herd animals is common practice in the area, Wolfe said. - KTVB.





GLOBAL VOLCANISM: Guatemala's Fuego Volcano Becoming More Active - Officials Warn Columns Of Ash Could Reach 15,000 Feet Above Sea Level!

AFP/AFP/File - Ash billowing from the Fuego volcano is seen from the Palin municipality, Escuintla departament, 40 km south of Guatemala City on February 13, 2015

May 15, 2015 - GUATEMALA
- Guatemala's Fuego volcano is becoming more active, belching out increasing amounts of smoke and ash, officials said on Friday.

Fearing a full-blown eruption of the volcano, located just 50 kilometers (30 miles) from the capital of Guatemala City, disaster officials warned that aircraft should exercise caution when flying over Fuego.

Conred, the national disaster coordination agency, said the volcano's eruptions could range in intensity from weak to moderate, and that columns of ash could reach 4,500 meters (15,000 feet) above sea level.

Authorities also warned that wind-borne ash particles could travel as far as 12 kilometers from the volcano, possibly causing respiratory and other health problems for some Guatemalans.

Fuego, which translates to "fire" in Spanish, measures more than 3,700 meters and is located in southwestern Guatemala on the borders of Chimaltenango, Escuintla and Sacatepequez departments.

Officials said for the moment there is no need to prepare for evacuations, but will continue to monitor the volcano since the situation could change quickly.

Fuego reawakened earlier this year, raining soot and ash on adjacent towns and forcing the temporary closure of a nearby airport. - Yahoo.


 

DELUGE: Ten Inches Of Rainfall In Just 24 Hours In Houston, Texas - One Person Killed!

Many vehicles submerged in flood waters on Gulf Freeway near Houston. © Johnny Kelly

May 15, 2015 - TEXAS, UNITED STATES
- Floods have left 1 man dead and prompted over 20 emergency rescues after staggering amounts of rainfall across south east Texas.

The state has seemingly been bombarded non stop with severe weather since flash floods hit Lubbock on 04 May 2015. One man died in floods in Corsicana on 11 May 2015 after 10 inches of rain fell in 1 day.

In the Houston area yesterday around 20 people had to be rescued from the flood water, most of them from stranded vehicles. Some major roads were said to be under 5 feet (1.5 metres) of water. Particularly badly hit were the areas of Taylor Lake Village, Webster and Clear Lake.

Rainfall

Webster, in the Houston metro area, saw 10.52 inches of rain fall for the 24 hours ending about 7 am Wednesday 13 May, 2015.
Several areas around Houston down to Galveston saw 24 hour rainfall levels of above 6 inches. Two days earlier, Onalaska saw 12.79 inches fall in 24 hours between 10 and 11 May.

National Weather Service Houston distributed the chart below to indicate the extreme levels of rain the area has seen in the last 3 days.


Extreme Rainfall Levels in Southern Texas, 11 to 14 May 2015.  © NWS / NOAA



Local media are reporting that the body of a man who went missing in the floods has been found. Alarms were raised when authorities found the empty car of the victim yesterday in the Clear Lake Area. Texas Equusearch have been searching for the missing man since then. It is thought the man had been swept away by the floods in the early hours of Wednesday 13 May 2015.

Social Media
Unbelievable images coming out of the Clear Lake area this morning. #flooding #kprc2 @KPRCRachel @KPRCBritta pic.twitter.com/p8I90KqmPH

— Jenelle Shriner (@JenelleKPRC) May 13, 2015

 
Unbelievable images coming out of the Clear Lake area this morning.  © Jenelle Shriner ‏

Developing: Many vehicles submerged in #flood waters on Gulf Freeway near Houston #TX http://t.co/Kmmy5US1PX #TXwx pic.twitter.com/ErdREuj9Ii

— Johnny Kelly (@stormchaser4850) May 13, 2015
  - Floodlist.