Editing Rub' al Khali (section)

==Description==
{{multiple image |align=right |direction=vertical |width=
 |image1=Rub al Khali 001.JPG |caption1=Typical pale gravel plains surrounded by huge sand dunes, as seen in the Emirate of Abu Dhabi
 |image2=Water in shaybah.JPG |caption2=Water found below ground level in the ''Rub' al-Khali'' in [[Shaybah]], Saudi Arabia
}}

===Terrain===
The desert is {{convert|1,000|km|mile|abbr=off}} long, and {{convert|500|km|mile|abbr=off}} wide.<ref name=":1">{{Cite web |title=Rub' al-Khali {{!}} Map, Location, Meaning, & Facts {{!}} Britannica |url=https://www.britannica.com/place/Rub-al-Khali |access-date=2024-07-22 |website=www.britannica.com |language=en}}</ref> Its surface elevation varies from {{convert|800|m}} in the southwest to around sea level in the northeast.<ref name = Desert>{{WWF ecoregion |name = Arabian Desert and East Sahero-Arabian xeric shrublands|id=pa1303|access-date=22 August 2010}}</ref> Most of the terrain is [[Erg (landform)|ergs]], with [[sand]] [[dune]]s up to {{convert|250|m}} high, interspersed with gravel and [[gypsum]] plains.<ref name = Lakes /><ref name = Desert /> The sand is reddish-orange due to the presence of [[feldspar]].<ref name = Desert />

There are also brackish salt flats in some areas, such as the [[Umm al Samim]] area on the desert's eastern edge.<ref name = Desert /> [[Ali Al-Naimi]] reports that the sand dunes do not drift. He goes on to say,
<blockquote>
Sand blows off the surface, of course, but the essential shape of the dunes remains intact, probably due to the moisture leaching up into the base of the dunes from the surrounding [[sabkha]]s.<ref name=Ali/>{{rp|213}}
</blockquote>

====Lake beds====
Along the middle length of the desert, there are several raised, hardened areas of [[calcium carbonate]], gypsum, [[marl]], or clay that were once the site of shallow lakes. These lakes existed during periods from 6,000 to 5,000 years ago and 3,000 to 2,000 years ago. The lakes are thought to have formed as a result of "cataclysmic rainfall" similar to present-day [[monsoon]] rains and most probably lasted for only a few years. However, lakes in the [[Mundafan|Mundafen]] area in the southwest of the Rub' al Khali show evidence of such lakes lasting longer, up to 800 years, from increased runoff from the [[Tuwaiq Escarpment]].<ref name = Lakes />

Evidence suggests that the lakes were home to a variety of flora and fauna. Fossil remains indicate the presence of several animal species, such as [[hippopotamus]], [[water buffalo]], and [[Aurochs|long-horned cattle]]. The lakes also contained small snails, [[ostracods]], and when conditions were suitable, [[freshwater clams]]. Deposits of calcium carbonate and [[opal]] [[phytolith]]s indicate the presence of plants and algae. There is also evidence of human activity dating from 3,000 to 2,000 years ago, including chipped [[flint]] tools, but no actual human remains have been found.<ref name = Lakes />

===Climate===
The region is classified as "[[hyper-arid]]", with annual precipitation generally less than {{convert|50|mm}}, and daily mean relative humidity of about 52% in January and 15% in June–July.<ref name=":1" />{{Failed verification|date=September 2024}}

===Biodiversity===
Fauna includes [[arachnid]]s (e.g. [[scorpion]]s) and [[rodents]], while plants live throughout the Empty Quarter. As an [[ecoregion]], the Rub' al Khali falls within the [[Arabian Desert|Arabian Desert and East Saharo-Arabian xeric shrublands]].<ref name = Desert /> The [[Asiatic cheetah]], once widespread in Saudi Arabia, is extirpated.<ref>Durant, S.; Mitchell, N.; Ipavec, A. & Groom, R. (2015). "''Acinonyx jubatus''". ''[[IUCN Red List|IUCN Red List of Threatened Species]]''. '''2015''': e.T219A50649567. [[Doi (identifier)|doi]]:10.2305/IUCN.UK.2015-4.RLTS.T219A50649567.en.</ref>

===Oil===
The [[Shaybah]] oil field was discovered in 1968. South [[Ghawar Field|Ghawar]], discovered in 1948, is the largest oil field in the world and extends southward into the northernmost parts of the Empty Quarter.<ref name=Ali/>{{rp|212,228}}

===Transport===
A road between Oman and Saudi Arabia,<ref name="TheNational 07-2021">{{cite news |last=Al Shaibany |first=Saleh |title=Oman-Saudi road to save 16 hours travel time nears completion: New road cuts through the Empty Quarter and will be a lifeline for trade between the two countries |publisher=[[The National (Abu Dhabi)|The National]] |url=https://www.thenationalnews.com/gulf-news/2021/07/06/oman-saudi-road-to-save-16-hours-travel-time-nears-completion/ |date=2021-07-06 |access-date=2021-11-09}}</ref><ref name="GulfNews 07-2021">{{cite news |last=Al Amir |first=Khitam |title=New Saudi-Oman road to cut land travel time by 16 hours: Travel between two countries to get lot easier; road is 800km in length |publisher=[[Gulf News]] |location=[[Dubai]], the [[United Arab Emirates|U.A.E.]] |url=https://gulfnews.com/world/gulf/saudi/new-saudi-oman-road-to-cut-land-travel-time-by-16-hours-1.80489647 |date=2021-07-07 |access-date=2021-11-09}}</ref> through the Empty Quarter, was completed in September 2021.<ref name="TheNational 09-2021">{{cite news |last=Al Shaibany |first=Saleh |title=Oman-Saudi desert road will breathe new life into sleepy villages: 700-km motorway to cut through the Empty Quarter, bringing trade to once-abandoned areas |publisher=[[The National (Abu Dhabi)|The National]] |url=https://www.thenationalnews.com/gulf-news/2021/09/06/desert-road-from-oman-to-saudi-arabia-will-breathe-new-life-into-sleepy-villages/ |date=2021-09-06 |access-date=2021-11-09}}</ref> Measuring between {{convert|700|and|800|km|mile|abbr=off}}, it extends from [[Ibri]] in Oman to [[Al-Ahsa Oasis|Al-Ahsa]] in [[Eastern Province, Saudi Arabia|eastern Saudi Arabia]]. A {{convert|160|km|mile|adj=on}} stretch of the road is on the Omani side and {{convert|580|km|mile|abbr=on}} is on the Saudi side.<ref name="TheNational 07-2021" /><ref name="GulfNews 07-2021" /> The road also goes through the [[archaeological Sites of Bat, Al-Khutm and Al-Ayn|archaeological sites of Bat, Al-Khutm and Al-Ayn]] in Oman.<ref name="TheNational 09-2021" />