Baja California and the Sea of Cortez

1. Baja California and the Sea of Cortez

2. Tijuana Ensenada San Felipe San Quintin El Rosario Bahia de Los Angeles Guerrero Negro Santa Rosalia Mulege Bahia Concepcion Bahia Magdalena La Paz Cabo San Lucas

3. Geology of Baja California

4. Pacific Plate moves NW past N. American Plate • San Andreas fault between

5. Early Miocene: • Part of shore or underwater • Some mountains as islands tropics Murphy, 1983 as quoted in Grismer, unpublished

6. Middle Miocene: • Mountains rose • Mainland subsided • Gulf began to form • S. peninsula separated from mainland, became island tropics Murphy, 1983 as quoted in Grismer, unpublished

7. Late Miocene: • Mountain chains connected, forming a contiguous peninsula tropics Murphy, 1983 as quoted in Grismer, unpublished

8. Miocene-Pliocene: • Rapid tectonic activity • Pacific plate moved north • Mountains rose more • Sea level rose, isolating south end • Gulf extended far north tropics Murphy, 1983 as quoted in Grismer, unpublished

9. Late Pliocene-Present: • Mountain uplift • Desertification • Gulf regressed • Temporary land bridges to islands tropics Murphy, 1983 as quoted in Grismer, unpublished

10. History of Baja California

11. Gúzman Cortez 1535 Becerra 1533 Cortez Mendoza 1532

12. English map 1641

13. English map 1641

14. Vizcaino 1596 Cabrillo 1542 Vizcaino 1602 Cavendish 1586 Mendoza galleons 1542 Francis Drake 1578

18. Oceanography of the Gulf of California/Sea of Cortez

22. California Province Caribbean Province Panamic Province

23. California Province Panamic Province Caribbean Province Gulf Invertebrates: • 21% endemic in gulf • 41% Panamic • 18% Californian • 4% Caribbean • 8% Cosmopolitan

25. Ebeling 1985

26. Ebeling 1985

27. Ebeling 1985

28. Ebeling 1985

29. Ebeling 1985

30. Prevailing Westerlies Typhoons

31. North: Rain winter & spring Pacific: Cool, foggy, surf Gulf: Dry, hot, calm Center: Dry South: Storms June-October