Table 1 Geological type and symbol of tide gauge and GPS receiver site in the study area.

Geological materials		Symbol of station type	Geological time			Stress history		Consolidation degree^d	Subsidence type
Geological materials		Symbol of station type	Period	Epoch	Start, MYBP	Experienced effective stress (\({\upsigma }_{{\text{c}}}^{{\prime}} )\)	Current effective stress (\({\upsigma }_{{\text{o}}}^{{\prime}} )\)	Consolidation degree^d	Subsidence type
Geological system	Aquifer systems	\({\text{Q}}_{{\text{h}}}\)	Quaternary	Holocene	0.00117	Very low	\({\upsigma }_{{\text{o}}}^{{\prime}} \approx {\upsigma }_{{\text{c}}}^{{\prime}}\)	1	SPC, SC_nBR	LS_nBR
		\({\text{Q}}_{{\text{p}}}\)	Quaternary	Pleistocene	2.58	Low		2
		\({\text{T}}\)	Tertiary	Pliocene to Paleocene	66	High		3
		\({\text{C}}\)	Cretaceous		145	Very high		4
		T^OC	Tertiary	Pliocene to Paleocene	66	High	\({\upsigma }_{{\text{o}}}^{{\prime}} < {\upsigma }_{{\text{c}}}^{{\prime}}\)	5	SC_nBR^a
		C^OC	Cretaceous		145	Very high		5	SC_nBR^a
	Bedrock system	pre-C	Jurassic to Precambrian		4600	Highest	\(\upsigma _{{\text{o}}}^{{\prime }} <\upsigma _{{\text{c}}}^{{\prime }} { }\) ^b \(\upsigma _{{\text{o}}}^{{\prime }} \approx\upsigma _{{\text{c}}}^{{\prime }}\) ^c	6	TS, SC_BR	LS_BR

LS_nBR—Land subsidence due to compaction of non-bedrock systems (aquifer systems); LS_BR—Land subsidence due to TS and SC_BR of the bedrock system. SC_nBR—Subsidence due to creep of non-bedrock systems (aquifer systems); SPC—Subsidence due to primary compaction; TS—Tectonic subsidence; and SC_BR—Subsidence due to creep of the bedrock system.
^aSC_nBR from the T^OC and C^OC strata in the human observation period is assumed to be insignificant after a long-term accumulative creep such as the length CD in Supplementary Fig. S3 after an overburden removal event.
^bIn the College Station, Texas area and the region from De Soto Canyon to Daytona Beach, Florida in Fig. 2.
^cIn the region from the west of Galveston Pier 21, Texas to De Soto Canyon, Florida in Fig. 2.
^dThe consolidation degree of geological strata is based on the strata’s stress history in column stress history of this Table 1; 1—Very unconsolidated; 2—Unconsolidated; 3—Semi-consolidated³⁵; 4—Highly semi-consolidated; 5—Over semi-consolidated; and 6—Consolidated (Bedrock).

Search