Is planet Earth on 'quake mode' again?Beijing, Apr 17(AZINS) Certain "high risk zones" around the world do require a close watch, geophysicists now believe after a spate of high-intensity earthquakes rattled different parts of the world and reignited the question whether the Earth is experiencing another round of seismic-active period.

During the past two months, unusually active seismic activities have been witnessed around the globe, with a string of powerful quakes jolting Ecuador, Japan, Myanmar, Indonesia, and Afghanistan, killing people and triggering tsunami alerts.

Many cannot help but wonder: Is this just coincidence, or is our planet once again on a "quake mode", that there will be one major tremor after another?

Experts find it difficult to draw a quick conclusion as predicting the quakes more accurately in time and space still remains a task for the future.

They, however, have noted that both the magnitudes and frequencies of the quakes were "within a normal range" but certain areas require a close watch.

It is hard to judge whether the Earth is experiencing another seismic-active period, Randy Baldwin, a geophysicist with the US Geological Survey, told China's state-run Xinhua news agency.

The last cycle of frequent earthquakes were witnessed in the first 60 years of the 20th century, when there were seven quakes above 8.5 on the Richter scale. In the following 40 years there were no major quakes.

Baldwin says quake-prone zones around the world could see strong shocks any time, but so far there have been no signs of connection between seismic activities in different zones.

Experts are divided on the causes of the quakes. They say it's complicated but point out the geographic location of Japan and Indonesia, both of which sit on the Circum-Pacific Seismic Belt, is the main reason behind such frequent tremors.

The belt, which extends all the way through the US Pacific coast, China's Taiwan, the Philippines and New Zealand, releases about three quarters of quake-discharged energy from the interior of our planet.It has earned a befitting name - the Pacific Ring of Fire.

Though it may seem too early to sound alarm for a new wave of disastrous earthquakes, some scientists insist that certain "high risk zones" do require attention.

The southern part of the Qinghai-Tibet Plateau in southwest China always has a high geological activeness, and is now entering a "clustering period" of massive quakes above magnitude 7.0, warned Xu Xiwei, a researcher at the Institute of Geology under the China Earthquake Administration.

"We have to make further studies to better understand the seismic trends in that region," Xu said.