Poole Bay

Poole Bayis a bay in theEnglish Channel,on the coast ofDorsetin southernEngland,which stretches 16km fromSandbanksat the mouth ofPoole Harbourin the west, toHengistbury Headin the east. Poole Bay is a relatively shallowembaymentand consists of steep sandstone cliffs and several 'chines' that allow easy access to the sandy beaches below. The coast along the bay is continuously built up, and is part of theSouth East Dorset conurbation,including parts of the towns ofPoole,BournemouthandChristchurch.

Poole Bay
Poole Bay
Coordinates	50°40′N1°52′W
Ocean/sea sources	English Chanel,Atlantic Ocean
Max. length	16 km (9.9 mi)
Settlements	Poole,Bournemouth

In terms of sand on England's south coast the bay presents the longest stretch; much exceeded by the total to the west across numerous bays and coves but greater than the three such stretches to the east,Avon Beach,West WitteringandCamber Sands.

History

Measures to preventcoastal erosionhave been deployed throughout the 20th century. Concrete seawalls andgroynesallowed the construction of homes and roads on the clifftops, but prevented natural supply of sand and gravel to the shore. From 1970 to 2000 over 1.5 million m³ of sand was used to replenish the beaches at Bournemouth and Poole. Many of the beaches along Poole Bay were replenished during the winters of 2005 and 2006 with 1.1 million m³ of sand dredged from Poole Harbour and 700,000 m³ of sand dredged from a Licensed Area off the Isle of Wight.In 2015 a 17-year £43.7million project was approved to protect the beaches from further erosion over the next century. The plans involve replacing the groynes and adding new ones and replenishing the beaches with 210,000 cubic metres of sand and gravel every three years.

Archaeology

In July 2022,marine archaeologistsfromBournemouth Universityunearthed the relics of a 750 years old medievalshipwreckand its cargo off the coast ofDorset.Definite date of the ship was determined bytree ring datingmethod. Due to the combination of low-oxygenated water, sand and stone, one of the whole sides of the ship was well preserved and the hull was prominently visible, according to archaeologist Tom Cousins. Known as theClinkership in its design, the ship was carrying a load ofPurbeck stones.Much of the cargo included manyPurbeck stonemortars,large stones used by mills to grind grain into flour.

Geology

The area of Poole Bay was predominantly created during thePleistoceneperiod, when the Solent river ran across the whole of South East Dorset and West Hampshire, out past theIsle of WightThe solid geology of the cliffs, and the seabed beneath Poole Bay, is composed of rocks of the TertiaryBracklesham Group,consisting of a sequence of fine, medium and coarse sands. AtHengistbury Headthere are younger rocks of the Bartonian group, forming an outlier. The Barton Clay here is made up of a series of sands and interbedded clays, with four distinct bands ofironstone nodules.These formations dip eastwards and are cut out by a north-west to south-east trending fault. This defines the eastwards boundary of Christchurch Ledge, which is a seawards continuation of the resistant ironstone strata exposed in Hengistbury Head.