They didn't "come up with" the 70-percent figure. That was done by another team at the University of Hawaii, as they cite very clearly. The focus here was on ambient shipping noise, not on the low frequency (10 Hz) waves covered in the previous paper. So no there isn't a 70-percent increase for waves in the 100-1000 Hz range, as they clearly state IN the paper. In fact, that was the point of this most recent work, to show that not just low frequency waves will propagate farther, ambient shipping noise will as well. And THIS research was published by the Acoustical Society of America, so yes THE acoustics guys do take them seriously. And your superiors in the Navy do as well: They sponsored it!