Cavite, Philippines --- Earthquakes of significance generally measure at least intensity 5 in Richter scale. Some say, however, at least intensity 4 is dangerous for the Pacific countries, including the Philippines.
Based on the records of United States Geological Survey (USGS), in the last four days, around 4 to 5 earthquakes hit the world in a day's time.
A total of 17 significant earthquakes have been recorded (PST time frame; 16 for UTC). And about 9 of these earthquakes came from Honshu, Japan. After Japan was hit by intensity 9 (upgraded by USGS from 8.9) earthquake on March 11, 2011, hundreds of aftershocks have been recorded since then. At least for April 2011, strength of earthquakes in Japan range between intensities 5.0 and 5.4.
In the last 24 hours, two countries have just been hit by two strong earthquakes. Yesterday,experienced an intensity 6.4 (from 6.2) earthquake around 10 p.m. (PST). While today, Java, Indonesia is hit by a stronger earthquake with intensity 6.7(from 7.1 BMKG measures) around 4 a.m. (PST).
A weak shaking (III MMI) was felt in Fiji Island. Earthquake was harmless and had a depth of 555 kms (hypocenter). Exact locations of affected areas based on Earthquake Report data are as follows:
approx. 30 km from Tuvuca
approx. 50 km from Vanua Balavu Island
252 km W of Lambasa, Vanua Levu, Fiji
321 km W of Suva, Viti Levu, Fiji
However, yesterday was not the first case of earthquake for Fiji this April 2011. A day before, the southern part of Fiji Islands was also struck by intensity 5.1 earthquake.
Meanwhile, earthquake strikes about 24 kms of southern region of Java. Epicenter is located at Indian Ocean, 250 km away from Indonesia. Based on USGS data, the following areas are affected:
241 km ENE of Christmas Island
277 km S of Tasikmalaya, Java, Indonesia
318 km S of Bandung, Java, Indonesia
412 km SSE of Jakarta, Java, Indonesia
Shaking in Indonesia premises is also recorded at intensities IV (light shaking in Cilacap and Pangandaran) and II (strong shaking in Karangkates, Denpasar, Jogja, Cisarua, and Purworejo).
Earthquake in Indonesia is earlier measured at 7.1. Because of this, tsunami alert had been raised in the southern region of Indonesia and in Australia, Malaysia, New Zealand and Singapore. Later, the Pacific Tsunami Warning Center lifted the alert.
On April 1, earthquakes struck Crete, Greece (intensity 5.9) and South Sandwich Islands Region (5.4).
Chile was hit twice by earthquakes on April 2. One was at Off shore Libertador O'Higgins (intensity 5.1) and the other, Tarapaca (intensity 5.9).
What appears to be quite crucial in all these phenomena is the fact that these recorded sesmic activities are nothing new for the year 2011.
Earthquakes have been frequenting Chile, Fiji Islands, Indonesia, and Japan in the first quarter of 2011. Offshore region of Chile was also stricken by intensity 5.4 earthquake on March 28, 2011. Fiji Regions was hit on March 31, 2011 by intensities 6.4 and 5.4 earthquakes. Southern part of Indonesia has recorded many seismic activities last March 2011. Japan is obviously under the spell of aftershocks and tremors.
What do these mean? Are new landforms soon to show up in the Pacific Coast? Will some islands submerge (and God forbid!)? Are these really natural phenomena?
Are these caused by climate change? But how? The earth is getting warmer causing contraction of the land mass below?
Are these caused by people? Is it really true that massive oil extraction left void spaces, shaking the earth?
Or are these the after effects of nuclear missle testing conducted for years underneath the earth's mantle?