Ground shaking in mainland India was muted except one with a magnitude of 4.5 on the Richter scale (M4.5) recorded in Satara district in Maharashtra.

But there was no respite for the Andaman and Nicobar Islands, thanks to its proximity with the Indonesian archipelago.

LARGE QUAKES

The latter sits on the ‘Pacific Ring of Fire,' known for the hyperactivity underneath as evidenced in historically large earthquakes and volcanic eruptions.

And Indonesia lived up to its name, having been shaken up big with an M8.5 on April 11 followed by an M8.1 two hours later.

An M6.1 intervened, which seemed to have taken some sting off the eventual M8.1.

In all, Indonesia recorded 10 quakes of M4.5 and above during April. The month of May, too, has started off with a bang with an M5.5 at Sulawesi on the first day.

FEWER RUMBLES

If Indonesia sneezes, Andaman and Nicobar Islands is sure to catch a cold. And so it proved!

The number of rumbles may have been fewer during the month, but all of them were of marked intensity of M5 and above. The strongest of them was an M5.8, recorded on April 25. It was preceded by an M5.5 only a day before.

Otherwise, mainland India was largely unaffected except for the M4.5 in Maharashtra, and a couple of shaking of lower intensity in Gujarat and Mumbai.

>vinson@thehindu.co.in

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