CRISISBOOM

Ring of Fire pictured left with earthquakes from last 7 days (right). Quake data by earthquakes.tafoni.net

Indonesia was hit by a large earthquake and a series of strong tremors Sunday afternoon. A 6.5 magnitude quake, the latest in string of strong quakes to hit the Pacific Ring if Fire region during the last week, struck the country’s easternmost Province of Papua 1.16 p.m. GMT.

The quake was centred 53 kilometres (33 miles) northeast of Waren, a town on the northern coast of Papua island, according to Indonesia’s Meteorology and Geophysics Agency.  It was also felt in nearby Biak island, and Enarotali town on the main island The U.S. Geological Survey put the initial quake’s magnitude at 6.4.

The region was hit by at least moderate tremors in the following hours. The tremors measured 5.4 (x2), 5, 4.5 and 4.3 on the Richter Scale. There were no immediate reports of damage and no tsunami warning was issued.

Papua comprises most of the western half of the island of New Guinea and nearby islands. Its capital is Jayapura.

Epicentre of Sunday’s quake. Image emsc-csem.org

Sunday’s quake follows a week of increased activity along the Pacfic Ring of Fire and comes less than 48 hours after a 7.2 magnitude earthquake struck Alaska, USA.

Among the other nations to record moderate to strong earthquakes during the last seven days are Japan, Fiji, Panama, Papua New Guinea, Costa Rica, Solomon Islands, Vanuatu, Tonga, Samoa, Chile, Peru, Bolivia, Argentina and Antarctica.

The “Ring of Fire” is an arc stretching from New Zealand, along the eastern edge of Asia, north across the Aleutian Islands of Alaska, and south along the coast of North and South America. The Ring of Fire is composed over 75% of the world’s active and dormant volcanoes.

The strongest earthquake to be recorded this week was the Alaska quake which hit the sparsely populated Fox Islands region of the Aleutian Islands Thursday night.  The epicentre, recorded at a depth of 62km, was located 64 km (39 miles) SW of Amukta Island, 103 km (64 miles) SW of Yunaska Island, and 1677 km (1042 miles) WSW of Anchorage, Alaska’s largest city.  The quake hit just two days after a 5.1 magnitude earthquake hit the Rat Islands region.

A tsunami warning issued for the west coast of North America from the Mexican border to Alaska soon after the quake struck was later cancelled.

Four earthquakes measuring in excess of 5.0 on the Richter Scale struck Alaska last week. A magnitude 5.1 earthquake hit at 8PM (11AM local time, Thursday 16 May). It’s epicentre was located 110km southwest of the State’s largest city Anchorage, 16km east of Nikiski (population 4327)  in the Kenai Peninsula Borough, and 28 km northeast of Kenai (population 7464).  The quake was recorded at a depth of 70km.  Three moderate quakes, two  5.1 magnitude quakes and a 5.2 magnitude quake, followed at 8.06PM. At least three earth tremors measuring 2-3 magnitude were recorded in the same area five minutes later.  The Alaska Earthquake Information Center said the event was widely felt in the Kenai Peninsula and Cook Inlet regions. The strongest shaking was experienced in the Peninsula communities of Sterling and Soldotna.

OTHER QUAKES ON THE PACIFIC RING OF FIRE

On Saturday night a 5.6 magnitude earthquake was recorded south of the Fiji Islands. On Wednesday night a magnitude 5.2 earthquake was recorded 126 km (78 miles) SSW of Ndoi Island, Fiji.  The region was also hit by 5.5 and 5.1 magnitude quakes on Saturday and Sunday respectively.

A large earthquake (magnitude 6.7) struck off the coast of Honshu, Japan, also on Wednesday night prompting authorities to issue a tsunami alert for the northeast of the country.  The quake epicentre was located 86 km (53 miles) SE (132°) from Hachinohe, Honshu, 100 km (62 miles) ENE (73°) from Morioka, Honshu, Japan, 161 km (100 miles) SE (126°) from Aomori, Honshu, and 527 km (328 miles) NNE (24°) from Tokyo.

A series of large tremors measuring greater than 5 on the Richter Scale have been recorded since Wednesday night’s earthquake, the latest a magnitude 5.6 in Hokkaido Friday evening. A 5.3 quake also struck close to the tsunami-stricken port city of Sendai on Wednesday. Japan is still reeling from the March 11 9 magnitude earthquake and tsunami which devastated parts of the north east.

Elsewhere, a 6.2 magnitude earthquake struck The Solomon Islands in the south-western Pacific Ocean Friday morning. The strong quake was centred 25 km (15 miles) SSE of the  provincial capital of the Santa Cruz Islands and 444 km (275 miles) E of Kira Kira, San Cristobal.  According to the US Geological Survey the quake was recorded at a depth of 62.6 km (38.9 miles).  It was the third strong earthquake to his the region this week. A 6.1 quake was recorded 93 km (57 miles) SSW of Lata on Tuesday morning while a 5.5 magnitude quake hit between the Santa Cruz Islands and Vanuatu on Monday evening.

The Santa Cruz Islands are part of Temotu Province of the Solomon Islands. They lie approximately 250 miles (400 km) to the southeast of the Solomon Islands Chain. The Santa Cruz Islands lie just north of the archipelago of Vanuatu, and are considered part of the Vanuatu rain forests ecoregion.

On Thursday night Tonga was hot by a moderate earthquake, which was recorded 102 km (63 miles) NNE of Hihifo and 229 km (142 miles) SW of Apia, Samoa.

The Catamarca region of Argentina also experienced a moderate earthquake on Wednesday afternoon. The 5.3 magnitude quake was centred 66 km (41 miles) SE of Belen, Catamarca, and 160 km (99 miles) NNE of La Rioja.

A 5.2 magnitude quake struck the South Island of New Zealand at 10.34 PM (local) on Tuesday. The quake epicentre was located 7km from Christchurch, which has been shaken by thousands of aftershocks since the February 22 quake that killed 181.  Earlier on Tuesday the Kermadec Islands Region of New Zealand experienced a magnitude 5 earthquake.

Also on Tuesday, northern Sumatra in Indonesia was shaken by a magnitude 5.2 tremor, located 109 km south of the city of Padang (population 840,352).

A strong earthquake struck the Antofagasta region of Chile Monday afternoon. The epicentre was located 87 km (54 miles) NE of Calama, Antofagasta, and 224 km (139 miles) SW of Uyuni, Bolivia.

A 5.4 magnitude quake hit the small south-western Pacific island nation of Vanuatu on Monday. The earthquake was centred 70 km NW of the town of Sola.

On Sunday a 5.1 magnitude earthquake struck 135 km (83 miles) south of David, Panama and 184 km (114 miles) SSE of Golfito, Costa Rica.

A 4.9 magnitude quake was recorded along the Pacific-Antarctic Ridge On Sunday afternoon, while a magnitude 5.1 tremor was also recorded in the Balleny Islands region, 479 km (297 miles) NW of Scott Island, on Saturday.

On Saturday night the northern coast of Peru experienced a moderate 5 magnitude earthquake which was felt 91 km away in the city of Piura.

On Saturday morning a magnitude 5.2 tremor was recorded in eastern New Guinea region of Papua New Guinea.  The quake struck 66 km (41 miles) NW of Lae and 355 km (220 miles) NNW of Port Moresby.

ANALYSIS

Earlier this week Irish Weather Online reported that 2011 is on target to record the largest number of earthquakes in a single year for at least 12 years.

Research by Irish Weather Online, using data from the US Geological Survey (USGS), has found that earthquake activity (5.0-9.9 magnitude) from 01 January to 19 June 2011 is already exceeding the total annual seismic activity for the years 2001, 2002 and 2003.  2011’s total number of recorded earthquakes is also expected to exceed the most seismically active year of the past 12 years, 2007.

A total of 1,445 earthquakes, ranging in magnitude from 5.0 to 9.9, have been recorded in the year up to 19 June. The total number of earthquakes recorded globally for the entire of 2007 was 2,270.