Powerful 7.8 M Quake Strikes New Zealand Region

Magnitude 7.8 M Earthquake Strikes Off West Coast of South Island, New Zealand

A powerful earthquake measuring magnitude 7.8 occurred off west coast of South Island, New Zealand, about 150 km  WNW of Invercargill, at 09:22:32 UTC, USGS reported.

The mainshock, which occurred at a depth of 35 km, was followed by a large aftershock measuring 5.8 Mw some 20 km WSW of the mainshock about 20 minutes later. [Location, 45.991°S, 166.238°E; depth, 35km; event ID, us2009jcat/USGS]

The aftershock was reported as measuring 6.1 on Richter scale, and at a depth of 5km, by New Zealand’s GNS Science Earthquake Information.

FEWW EarthModel simulations suggest the latest earthquakes may well be a prelude to an extended period of intense, likely catastrophic, seismic and volcanic activities in the New Zealand region. Lots of ‘fireworks’ may follow.  [See links below for forecasts and travel advisories.]

On May 9, 2009, FEWW Moderators issued the following warning to tourists planning to visit New Zealand:

A Warning to Visitors to New Zealand:

Climatological and Geological Warning! The New Zealand region is about to experience significant climatological events and large-scale geological and tectonic activity over an extensive period of time. Would be visitors are advised to stay out of the area for the foreseeable future.  http://newzeelend.wordpress.com/2009/05/09/a-warning-to-new-zealand-visitors/

New Zealand’s Alpine Fault – Source: Stuff NZ. Image may be subject to copyright. SEE Fair Use Notice!

What the local experts said

It’s interesting and quite comforting [sic] to note, as our colleague TERRES pointed out earlier, the local experts had assured New Zealanders “there was no cause for worry,”  and that the frequent quakes earlier this year were not “leading up to the ‘big one.'” http://www.stuff.co.nz/national/2308107/Quakes-no-cause-for-worry

10-degree Map Centered at 45°S,165°E

Earthquake Location. Original Map: USGS – EHP

Earthquake Details:

• Magnitude: 7.8
• Date-Time:
  • Wednesday, July 15, 2009 at 09:22:32 UTC
  • Wednesday, July 15, 2009 at 08:22:32 PM at epicenter

• Location: 45.721°S, 166.643°E
• Depth: 35 km (21.7 miles) set by location program
• Region:  OFF WEST COAST OF THE SOUTH ISLAND, N.Z.
• Distances:
  • 150 km (95 miles) WNW of Invercargill, New Zealand
  • 175 km (110 miles) WSW of Queenstown, New Zealand
  • 300 km (185 miles) W of Dunedin, New Zealand
  • 825 km (510 miles) SW of WELLINGTON, New Zealand

• Location Uncertainty:  horizontal +/- 11.1 km (6.9 miles); depth fixed by location program
• Parameters: NST= 44, Nph= 44, Dmin=322.8 km, Rmss=1.58 sec, Gp= 54°, M-type=teleseismic moment magnitude (Mw), Version=7
• Source: USGS NEIC (WDCS-D)
• Event ID:  us2009jcap

Seismic Hazard Map [USGS]

Major Tectonic Boundaries: Subduction Zones -purple, Ridges -red and Transform Faults -green

Population exposure estimates are NOT a direct estimate of earthquake damage; comparable shaking will result in significantly lower losses in regions with well built structures than in regions with vulnerable structures. [USGS]

Notes:

On September 30, 2008, FEWW wrote:

Magnitude 7 Earthquake Hits Kermadec Islands

Implication for New Zealand Islands:

• A substantial increase in the frequency of earthquake striking the twin islands.
• More earthquakes with magnitude 6 or larger.
• A marked increased in large explosive volcanic eruptions, especially in the following zones [also includes ‘extinct’ volcanoes]
  • Taupo Volcanic Zone
  • Bombay Hills
  • Auckland volcanic field
  • Mount Taranaki
  • Mt Horrible volcano
  • Mount Taranaki
  • Mount Cargill

Worst Case Condition for New Zealand Islands:

Will a magnitude 9.8 (M_W) earthquake centered at 42° 00′ 59″ South, 175° 05′ 07″ East herald the end of New Zealand Islands?

• Large earthquakes and massive volcanic eruptions could potentially destroy much of New Zealand structures and claim many lives.
• Earthquake and volcano-triggered waves could also give rise to 40 to 50-meter tsunami that would engulf the coastal areas and low-lying lands throughout New Zealand [could also affect parts of Australia’s eastern seaboard,] compounding the damage.
• A super/mega colossal Plinian/Ultra-Plinian eruption occurring in New Zealand’s North Island simultaneously [or within a short period of time] with a magnitude 9.8 earthquake off the eastern coast of New Zealand could claim many lives.
• Probability of occurrence:
  1. Event 1.  A magnitude 9.8 earthquake striking off the eastern coast of New Zealand with (i) the foreshocks ripping through Auckland, Hamilton, Taupo areas, (ii) the mainshock leveling Wellington, Palmerstone North, Marlborough, Nelson and Christchurch, and (iii) the aftershock causing substantial damage as far south as Invercargill: 85%
  2. Event 2. A super/ mega colossal Plinian/Ultra-Plinian eruption in the North Island: 72%  [South Island: 57%]
  3. Event 1 and Event 2 occurring simultaneously, or within a short period of time: 64 %

Related News Links:

• New Zealand quake tsunami warnings canceled

Related Links:

• California Earthquake Forecast 2009 [See also the comments section]
• FEWW Earthquake Links

• Magnitude 7 Earthquake Hits Kermadec Islands
• Magnitude 6.8 Quake strikes Kermadec Isls Region

• New Zealand Hit by another Quake
• Mag 5.3 Earthquake Rattles North Island, NZ

• Earthquake Cluster Zone Closing in on New Zealand
• Magnitude 7 Earthquake Hits Kermadec Islands

• Mt Ruapehu Eruption Alert [See also the comments section]
  

Killer Drought in Africa

Drought is the biggest environmental catastrophe facing Africa

A weak rainy season lead to water food shortages in most parts of Africa, especially Kenya, which entered a state of emergency with about a third of the country’s 32 million population requiring food aid.

The drought also meant low water levels in reservoirs, water rationing and power cuts. The Masinga hydroelectric dam was closed down after low water levels in the reservoir could not sustain power generation.

The following images show how plants responded to the poor rainfall during the rainy season in 2009.

Drought in Africa

Rainfall Anomaly (2009 season)

Cumulative Rainfall, Masinga Dam, Kenya

Africa’s Sahel region, a belt of fertile grassland, thrives or fails depending on seasonal rainfall. In dry years, little grows, and those who depend on rain to grow crops in the Sahel may face hunger.

Above images show rainfall during the long rainy season in 2009.  The top image, made from data collected by the Advanced Very High Resolution Radiometer (AVHRR) flying on the National Oceanic and Atmospheric Administration’s Polar Orbiting Environmental Satellite NOAA-17, shows the condition of plants in June 2009 compared to previous Junes. In areas that are brown, plants were growing less then the  2003 and 2008 average. Green areas indicate better-than-average growth, while cream-colored areas indicate about average growth.

The poor growth in June 2009 is a result of the weak rainy season. Low seasonal rains, which usually come between March and June, resulted in drought this year. Made from a combination of satellite and rain gauge measurements, the middle image shows the extent of the rainfall deficit between March and June. Areas in brown received less rain than average, while blue areas received more rain. The average was calculated from rainfall observed between March and June from 1995 through 2008. The northern Sahel and East Africa were drier than normal throughout the 2009 rainy season.

The graph illustrates why water levels were so low at Masinga Dam in 2009 compared to the long-term average and other recent years. Each line shows how the rainy season developed between March and June. 1997 was an unusually wet year, with about 75 millimeters more rain than average by the end of June. The last year when rainfall reached normal levels was 2006. In 2009, the rainy season didn’t start until late March and less rain fell throughout the season. By the end of June, Masinga Dam had only received about 100 millimeters of rain, about 125 mm less than average and 200 mm less than in 1997. If conditions improve, Kenya’s next rainy season will likely begin in September or October and will last through November or December.

Images created by Jesse Allen, using GIMMS NOAA-17 AVHRR and Africa Rainfall Estimate data provided by Ed Pak, Jennifer Small and Assaf Anyamba, NASA GIMMS Group at Goddard Space Flight Center. Caption by Holli Riebeek with information from Assaf Anyamba. Images acquired March 1, 2009 – June 30, 2009. [Caption edited for brevity by FEWW. ]

Related Links:

• Drought and Deluge