Sequence of five quakes near Palomar Observatory today

1.0 2013/05/15 18:15:33 33.377N 116.835W 7.0 4 km ( 2 mi) NE of Palomar Observatory, CA
1.0 2013/05/15 17:43:29 33.378N 116.838W 9.6 4 km ( 2 mi) NE of Palomar Observatory, CA
1.1 2013/05/15 17:33:59 33.376N 116.830W 7.1 4 km ( 2 mi) NE of Palomar Observatory, CA
2.9 2013/05/15 17:30:33 33.371N 116.841W 6.9 3 km ( 2 mi) NE of Palomar Observatory, CA
1.9 2013/05/15 17:20:09 33.374N 116.837W 6.8 3 km ( 2 mi) NE of Palomar Observatory, CA

Interestingly, I was hiking in the Santa Ana Mountains today and I heard, not felt, every one of them. I was about 52 miles (84km) away. I could distinctly tell which direction the sound came from. When I got home I heard about there being a 4.0 and at first thought it might be that until I looked it up and found the times to be wrong, as well as the direction.

It kinda sounded like very distant fireworks, but WAY lower in frequency. No thud or thump. More like a pressure change in the ear.

Brian