High Relief (IMAGE) Columbia Climate School Caption Alternating ridges and valleys formed by volcanism near the East Pacific Rise, a mid-ocean ridge in the Pacific Ocean. Such formations indicate ancient highs and lows of volcanic activity. Credit Haymon et al., NOAA-OE, WHOI Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.