noun
minor earthquake; small earthquake
Refers to an earthquake of low magnitude, typically one that causes little or no damage. Often used in news reports and everyday conversation.
今朝、小地震があったが、ほとんどの人は気づかなかった。
There was a minor earthquake this morning, but most people didn't notice it.
この地域では小地震が頻繁に発生している。
Minor earthquakes occur frequently in this region.
地震 is the general term for 'earthquake', while 小地震 specifies a small-scale one.
Compound of 小 (small) + 地震 (earthquake). The reading しょうじしん follows standard on'yomi.