A pair of earthquakes rattled the Morongo Basin and nearby Big Bear last night. The first, a magnitude 3.8 earthquake jolted Big Bear Lake shortly after 1 p.m. Monday, according to the U.S. Geological Survey. Originally listed at 3.9, it was later downgraded to 3.8. The epicenter of the quake reported at 1:08 p.m. was one mile east southeast of Big Bear Lake. The second quake hit 3 miles north of Yucca Valley, 22 miles west of Twentynine Palms, at 3:31 pm. While Sheriff officials received dozens of calls about the quakes, there were no immediate reports of damage or injury.