Question: The Lötschenlücke connects the Lötschental to the valley of a glacier with a length of about what in 2014?

Context paragraphs:
Aletsch Glacier: The Aletsch Glacier (German: "Aletschgletscher" ) or Great Aletsch Glacier ("Grosser Aletschgletscher ") is the largest glacier in the Alps.  It has a length of about 23 km (2014), has about a volume of 15.4 km3 (2011), and covers about 81.7 km2 (2011) in the eastern Bernese Alps in the Swiss canton of Valais.  The Aletsch Glacier is composed of four smaller glaciers converging at Concordia Place, where its thickness was measured by the ETH to be still near 1 km .  It then continues towards the Rhône valley before giving birth to the Massa.  The Aletsch Glacier is – like most glaciers on this world – a retreating glacier.  As of 2016, since 1980 it lost 1.3 km of its length, since 1870 3.2 km , and lost also more than 300 m of its thickness.

Dusty Glacier: Dusty Glacier is located on northeast slopes of Glacier Peak in the U.S. state of Washington.  The glacier descends from 9022 ft to 6430 ft and in places along its length is connected to North Guardian Glacier which lies to its south and Ermine Glacier to the north.  As is true with all the glaciers found on Glacier Peak, Dusty Glacier is retreating.  During the Little Ice Age, Dusty Glacier extended down to an altitude of 4800 ft , but since approximately the year 1850, the glacier has been in a general state of retreat and has lost more than 1500 m of its length.  Dusty Glacier is heavily crevassed and the glacier ends in an ice fall at its terminus.

Traffic Circle (Antarctica): Traffic Circle is a glacier-filled expanse 500 m high, situated south of Mount Ptolemy and medially on Antarctic Peninsula between Marguerite Bay and Mobiloil Inlet.  Hub Nunatak rises from the center of the Traffic Circle.  From this position, five glacial troughs radiate like the spokes of a wheel.  One connects on the north with Gibbs Glacier and Neny Glacier, leading to Neny Fjord.  Another connects on the west with Lammers Glacier and Windy Valley, leading to Mikkelsen Bay.  A third, Cole Glacier, trends southwest along Godfrey Upland toward the Wordie Ice Shelf area.  The fourth, Weyerhaeuser Glacier, trends southward toward Wakefield Highland and connects with glaciers leading westward to Wordie Ice Shelf.  The fifth, Mercator Ice Piedmont, is nourished by the outflow from Weyerhaeuser, Cole and Gibbs Glaciers; it broadens as it descends eastward to the head of Mobiloil Inlet.  Discovered in 1940 by members of the East Base party of the United States Antarctic Service (USAS), 1939–41, who used this system of troughs in traveling across the upland, hence the name Traffic Circle.

Bietschhorn: The Bietschhorn (3,934 m) is a mountain in canton Wallis to the south of the Bernese Alps in Switzerland.  The northeast and southern slopes of the mountain are part of the Jungfrau-Aletsch Protected Area (formerly "Jungfrau-Aletsch-Bietschhorn") listed as a UNESCO World Heritage Site that also includes the Jungfrau and the Aletsch Glacier.  The Bietschhorn is located on the south side of the Lötschental valley and form part of the UNESCO World Heritage Region at the north end of the Bietschtal valley and Baltschiedertal valley.  Most climbers approach the mountain from either the Bietschhornhütte or the Baltschiederklause.

Whitney Glacier: The Whitney Glacier is a glacier situated on Mount Shasta, in the U.S. state of California.  The Whitney Glacier is the longest glacier and the only valley glacier in California.  In area and volume, it ranks second in the state behind the nearby Hotlum Glacier.  In 1986, the glacier was measured to be 126 ft deep and over three km in length.  The glacier starts on Mount Shasta's Misery Hill at 13700 ft and then it flows northwestward down to the saddle between Mount Shasta and Shastina.  There is a major icefall that occurs there since the ground is very uneven at 11800 ft .  Past the icefall, the glacier flows down the valley between Mount Shasta and Shastina with the terminus at 9500 to .

Breithorn (Blatten): The Breithorn (3,785 m) is a mountain of the Bernese Alps, located east of Blatten in the canton of Valais.  It lies between the Bietschhorn and the Schinhorn, on the range separating the Lötschental (valley, north) from the main Rhone valley (south).  Its summit is the tripoint between the Lötschental and two other smaller valleys: the Baltschiedertal and the valley of the Beichgletscher.

Lötschenlücke: The Lötschenlücke (el.  3164 m.) is a high mountain pass of the Bernese Alps, connecting the Lötschental to the valley of the Aletsch Glacier in the canton of Valais.  Both sides of the pass are covered by glaciers: the Langgletscher on the west and the Grosser Aletschfirn on the east.  The Lötschenlücke lies between the Mittaghorn on the north and the Sattelhorn on the south.

Hollandia Hut: The Hollandia Hut (German: "Hollandiahütte") is a mountain hut of the Swiss Alpine Club, located east of Blatten in the canton of Valais.  The hut lies at a height of 3,240 metres above sea level, just above the Lötschenlücke, the glacier pass connecting the Lötschental from the Aletsch Glacier.  All accesses to the hut involve glacier crossing.

Kalabaland Glacier: Kalabaland Glacier of Himalaya is situated in the eastern Kumaun of the Pithoragarh district of Uttarakhand state of India.  Kalabaland is situated to the north of the Milam Valley and to the west of the Darma valley.  This glacier is aligned at northwest to southeast direction and lies above the Yankcharand Sankalp glaciers.  This glacier is rare in the fact that it joins with the Yankchar Glacier to form the Sankalp Glacier.  It is a massive mixed glacial system of Kalabaland-Burfu and Kalganga glaciers.  The length of the glacier is 15 km .  A number of peaks surrounding the Kalabaland Glacier are Bamba Dhura 6,334 m, Chiring We 6,559 m, Suli Top 6,300 m, Trigal 5,983 m, Burphu Dhura 6,144 m, Suitilla 6,373 m and Kalabaland Dhura 6,105 m. Kalabaland Glacier is nestled by the horseshoe-shaped Himalayan massif separating Goriganga and Lassar Yankti valleys, and it lies a little to the east of the Milam Glacier.  The Ralam Gad River originates from the Kalabaland, Yangchar and Sankalp glaciers.

Kennedy Glacier (Washington): Kennedy Glacier is located on northwest slopes of Glacier Peak in the U.S. state of Washington.  As is true with all the glaciers found on Glacier Peak, Kennedy Glacier is retreating.  During the Little Ice Age, Kennedy Glacier extended down to an altitude of 4314 ft and was connected to Scimitar Glacier to the south.  From about 1850 to 1952, the glacier lost 5577 ft of its length.  During a cooler and wetter period from 1952 to 1984, Kennedy Glacier advanced 1050 ft but between 1984 and 2005, the glacier again retreated, losing 1450 ft of its length.

Supporting paragraphs: Lötschenlücke Aletsch Glacier
Answer: 23 km