Encore - Tides Near Port Orford, Oregon

May 20, 2017

EPOD_EncoreTides Near Port Orford, Oregon

Today, and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Photographer: Randy Scholten  
Summary AuthorRandy Scholten

December 2011 Earth Science Picture of the Day Viewer's Choice The photo above shows Brush Creek rushing across a wide beach at low tide near Port Orford, Oregon. It was snapped at the base of Humbug Mountain a little past sunset on November 28, 2011. Venus and the waxing crescent Moon are conspicuous in the twilight sky.

Times and amplitudes of the tides are primarily influenced by the alignment of the Sun and Moon. The combined gravitational pull of these bodies when the Moon is full or new create higher amplitude tides than when the Moon is in other phases. Only nine percent of the Moon was illuminated, as shown above, just three days following the onset of the new Moon. A minus 1.2 ft (0.4 m) tide (low tide) was recorded here a few hours after the photo was taken. However, during the new Moon, the low tide was considerably more extreme (referred to as the spring tide), dropping to minus 2.1 ft (0.6 m) with a tidal range of 11.1 ft (3.4 m). [Revised April 2017]

Photo Details: Nikon D700 camera; 20 mm f/2.8D wide angle Nikkor lens; 1/5 sec. exposure; f/2.8; ISO 400. Note that sunset on November 28 was at 4:47 p.m. while moonset occurred at 8:41 p.m.