Stein / Blackman / Inagaki Earth and Life Processes Discovered from Subseafloor Environments

A Decade of Science Achieved by the Integrated Ocean Drilling Program (IODP)
1. Auflage 2014
ISBN: 978-0-444-62611-0
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 7, 822 Seiten

Reihe: Developments in Marine Geology

The Integrated Ocean Drilling Program (IODP: 2000-2013) has provided crucial records of past and present processes and interactions within and between the biosphere, cryosphere, atmosphere, hydrosphere and geosphere. Research in IODP encompasses a wide range of fundamental and applied issues that affect society, such as global climate change, biodiversity, the origin of life, natural hazards involving the study of earthquakes processes, and the internal structure and dynamics of our planet. This compilation of major findings from the 2003-2013/14 phase of IODP, focusing on scientific results rather than description of data acquisition and early inferences, provides invaluable information. Anyone wondering what scientific drilling can achieve will gain quick understanding of the range of questions that are uniquely addressed with this methodology and the ways these data dovetail with other regional information. The excitement of breakthrough findings that occasionally accompanies a drilling project will be evident. IODP obtained unique records from the global ocean basins during the 2003-2013 program phase. This book highlights findings in three theme areas: Subseafloor life and the marine biosphere; Earth's changing environments; and Dynamics of the solid Earth. Each core or borehole log provides a window revealing insights that no other data achieve. - Presents syntheses of key results from the Integrated Ocean Drilling Program - Encompasses a wide range of issues that affect society - Describes the Integrated Ocean Drilling Program and its expeditions

Autoren/Hrsg.

Stein, Ruediger

Blackman, Donna

Inagaki, Fumio

Larsen, Hans-Christian

Inhaltsverzeichnis

1;Front Cover;1
2;Earth and Life Processes Discovered from Subseafloor Environments;4
3;Copyright;5
4;Contents;6
5;Contributors;16
6;Preface;20
7;Acknowledgments;22
8;List of Reviewers;24
9;Chapter 1 - Major Scientific Achievements of the Integrated Ocean Drilling Program: Overview and Highlights;26
9.1;1.1 INTRODUCTION;26
9.2;1.2 THE DEEP BIOSPHERE AND THE SUBSEAFLOOR OCEAN (INITIATIVES IN DEEP BIOSPHERE AND GAS HYDRATES);29
9.3;1.3 ENVIRONMENTAL CHANGE, PROCESSES, AND EFFECTS (INITIATIVES IN EXTREME CLIMATES AND RAPID CLIMATE CHANGE);35
9.4;1.4 SOLID EARTH CYCLES AND GEODYNAMICS (INITIATIVES IN CONTINENTAL BREAKUP AND SEDIMENTARY BASIN FORMATION, LIPS, 21ST CENTURY M...;43
9.5;1.5 BOREHOLE OBSERVATORY ACCOMPLISHMENTS;53
9.6;REFERENCES;54
10;Chapter 2 New Frontier of Subseafloor Life and the Biosphere;62
10.1;Chapter 2.1 Exploration of Subseafloor Lifeand the Biosphere ThroughIODP (2003–2013);64
10.1.1;2.1.1 BACKGROUND: THE DEEP SUBSEAFLOOR BIOSPHERE;64
10.1.2;2.1.2 IODP EXPEDITIONS RELATIVE TO THE DEEP-BIOSPHERE RESEARCH;69
10.1.3;2.1.3 SAMPLE STORAGE FOR THE FUTURE DEEP-BIOSPHERE RESEARCH;79
10.1.4;2.1.4 CONCLUSION AND PERSPECTIVES;80
10.1.5;ACKNOWLEDGMENTS;81
10.1.6;REFERENCES;82
10.1.6.1;Chapter 2.2.1 - Biomass, Diversity, and Metabolic Functions of Subseafloor Life: Detection and Enumeration of Microbial Cells in Subseafloor Sediment;90
10.1.6.1.1;Detection and Enumeration of Microbial Cells in Subseafloor Sediment;90
10.1.6.1.2;2.2.1.1 THE HISTORY OF DETECTION AND ENUMERATION OF MICROBIAL CELLS IN DEEP SUBSEAFLOOR SEDIMENT;90
10.1.6.1.3;2.2.1.2 TECHNICAL CHALLENGES IN ESTIMATING BIOMASS AND MICROBIAL DIVERSITY IN SUBSEAFLOOR ENVIRONMENTS;94
10.1.6.1.4;2.2.1.3 COUNTING STATISTICS;96
10.1.6.1.5;2.2.1.4 OVERCOMING THE LIMITATIONS;97
10.1.6.1.6;2.2.1.5 COMBATING CONTAMINATION;98
10.1.6.1.7;2.2.1.6 LOWERING THE QUANTIFICATION LIMIT;99
10.1.6.1.8;2.2.1.7 POTENTIAL ALTERNATIVES FOR DETECTING LIFE IN SUBSURFACE ENVIRONMENTS;101
10.1.6.1.9;2.2.1.8 CONCLUDING REMARKS;103
10.1.6.1.10;REFERENCES;103
10.1.6.2;Chapter 2.2.2 - Genetic Evidence of Subseafloor Microbial Communities;110
10.1.6.2.1;2.2.2.1 RIBOSOMAL RNA AS PHYLOGENETIC MARKER;110
10.1.6.2.2;2.2.2.2 FUNCTIONAL GENES;121
10.1.6.2.3;2.2.2.3 METAGENOMIC INVESTIGATIONS OF COMPLEX SUBSEAFLOOR COMMUNITIES;134
10.1.6.2.4;REFERENCES;138
11;Chapter 2.3 - The Underground Economy (Energetic Constraints of Subseafloor Life);152
11.1;2.3.1 INTRODUCTION;152
11.2;2.3.2 ENERGY-CONSERVING ACTIVITIES IN MARINE SEDIMENT;152
11.3;2.3.3 LIFE UNDER EXTREME ENERGY LIMITATION;160
11.4;2.3.4 DISCUSSION;165
11.5;2.3.5 CONCLUSIONS;169
11.6;ACKNOWLEDGMENTS;169
11.7;REFERENCES;169
12;Chapter 2.4 - Life at Subseafloor Extremes;174
12.1;2.4.1 INTRODUCTION;174
12.2;2.4.2 POSSIBLE PHYSICAL AND CHEMICAL CONSTRAINTS ON LIFE IN SUBSEAFLOOR ENVIRONMENTS;175
12.3;2.4.3 CHALLENGE FOR LIMITS OF BIOSPHERE IN OCEAN DRILLING EXPEDITIONS OF ODP AND IODP;181
12.4;2.4.4 THERMODYNAMIC ESTIMATION OF ABUNDANCE AND COMPOSITION OF MICROBIAL METABOLISMS IN SUBSEAFLOOR BOUNDARY BIOSPHERE;185
12.5;2.4.5 CONCLUDING REMARKS AND PERSPECTIVES;193
12.6;REFERENCES;194
13;Chapter 2.5 - Life in the Ocean Crust: Lessons from Subseafloor Laboratories;200
13.1;2.5.1 INTRODUCTION;200
13.2;2.5.2 GENERAL OVERVIEW OF THE DIVERSITY, ACTIVITY, AND ABUNDANCE OF MICROBIAL LIFE IN IGNEOUS OCEANIC CRUST;201
13.3;2.5.3 SUBSEAFLOOR OBSERVATORIES: ANOTHER TOOL FOR STUDYING LIFE IN OCEANIC CRUST;205
13.4;2.5.4 RECENT DEEP BIOSPHERE DISCOVERIES FROM SUBSEAFLOOR OBSERVATORIES;209
13.5;2.5.5 THE FUTURE OF SUBSEAFLOOR LABORATORIES FOR DEEP BIOSPHERE RESEARCH;214
13.6;2.5.6 THE SIZE OF THE DEEP BIOSPHERE HOSTED IN IGNEOUS OCEANIC CRUST;215
13.7;2.5.7 CONCLUSIONS;215
13.8;REFERENCES;216
14;Chapter 2.6 - Cultivation of Subseafloor Prokaryotic Life;222
14.1;2.6.1 THE NECESSITY OF CULTURING SUBSEAFLOOR PROKARYOTES;222
14.2;2.6.2 THE SPECIFIC CHALLENGES TO CULTIVATE PROKARYOTIC LIFE FROM THE SUBSEAFLOOR;225
14.3;2.6.3 CULTIVATION ATTEMPTS USING CONVENTIONAL BATCH-TYPE CULTIVATION;226
14.4;2.6.4 METABOLIC CAPABILITIES OF AVAILABLE ISOLATES FROM SUBSEAFLOOR SEDIMENTARY ENVIRONMENTS;228
14.5;2.6.5 NOVEL TECHNIQUES FOR THE CULTIVATION OF SUBSEAFLOOR PROKARYOTIC LIFE;230
14.6;REFERENCES;234
15;Chapter 2.7 - Biogeochemical Consequences of the Sedimentary Subseafloor Biosphere;242
15.1;2.7.1 INTRODUCTION;242
15.2;2.7.2 BIOGEOCHEMICAL ZONATION IN SUBSEAFLOOR SEDIMENTS;244
15.3;2.7.3 SECONDARY BIOGEOCHEMICAL REACTIONS;247
15.4;2.7.4 INTERACTION OF BIOGEOCHEMICAL PROCESSES AND THE SEDIMENT;248
15.5;2.7.5 TIME AND THE DEEP SUBSEAFLOOR BIOSPHERE;256
15.6;2.7.6 BEYOND INTERSTITIAL WATER AND SOLID PHASE CHEMISTRY?;259
15.7;2.7.7 CONNECTING THE PELAGIC OCEAN AND SUBSEAFLOOR SEDIMENTARY OCEAN;262
15.8;2.7.8 TOWARD A GLOBAL OCEAN VIEW;265
15.9;ACKNOWLEDGMENTS;266
15.10;REFERENCES;266
16;Chapter 3 Environmental Change, Processes and Effects;278
16.1;Chapter 3.1 Introduction: Environmental Change, Processes and Effects—New Insights From Integrated Ocean Drilling Program (2003–2013);280
16.2;Chapter 3.2 - Cenozoic Arctic Ocean Climate History: Some Highlights from the Integrated Ocean Drilling Program Arctic Coring Expedition;284
16.2.1;3.2.1 INTEGRATED OCEAN DRILLING PROGRAM EXPEDITION 302: BACKGROUND AND OBJECTIVES;284
16.2.2;3.2.2 MAIN LITHOLOGIES AND STRATIGRAPHIC FRAMEWORK OF THE ACEX SEQUENCE;290
16.2.3;3.2.3 HIGHLIGHTS OF ACEX STUDIES;293
16.2.4;3.2.4 OUTLOOK: NEED FOR FUTURE SCIENTIFIC DRILLING IN THE ARCTIC OCEAN;307
16.2.5;ACKNOWLEDGMENTS;310
16.2.6;REFERENCES;310
16.3;Chapter 3.3 - From Greenhouse to Icehouse at the Wilkes Land Antarctic Margin: IODP Expedition 318 Synthesis of Results;320
16.3.1;3.3.1 INTRODUCTION;320
16.3.2;3.3.2 EXPEDITION 318 SUMMARY OF RESULTS;326
16.3.3;3.3.3 DISCUSSION OF RESULTS;341
16.3.4;3.3.4 CONCLUDING REMARKS;344
16.3.5;ACKNOWLEDGMENTS;346
16.3.6;REFERENCES;347
16.4;Chapter 3.4 - The Pacific Equatorial Age Transect: Cenozoic Ocean and Climate History (Integrated Ocean Drilling Program Expeditions 320 & 321);354
16.4.1;3.4.1 INTEGRATED OCEAN DRILLING PROGRAM EXPEDITIONS 320 & 321 INTRODUCTION: BACKGROUND, OBJECTIVES, AND DRILLING STRATEGY;354
16.4.2;3.4.2 MAIN SEDIMENT SEQUENCE;362
16.4.3;3.4.3 RESULTS FROM POSTCRUISE INVESTIGATIONS;364
16.4.4;3.4.4 OUTLOOK;375
16.4.5;ACKNOWLEDGMENTS;376
16.4.6;REFERENCES;376
16.5;Chapter 3.5 - North Atlantic Paleoceanography from Integrated Ocean Drilling Program Expeditions (2003–2013);384
16.5.1;3.5.1 INTRODUCTION;384
16.5.2;3.5.2 IODP EXPEDITION 303/306 (NORTH ATLANTIC CLIMATE);386
16.5.3;3.5.3 IODP EXPEDITION 339 (MEDITERRANEAN OUTFLOW);404
16.5.4;3.5.4 IODP EXPEDITION 342 (PALEOGENE NEWFOUNDLAND SEDIMENT DRIFTS);408
16.5.5;3.5.5 SUMMARY;410
16.5.6;ACKNOWLEDGMENTS;411
16.5.7;REFERENCES;411
16.6;Chapter 3.6 - Coral Reefs and Sea-Level Change;420
16.6.1;3.6.1 INTRODUCTION/RATIONALE;420
16.6.2;3.6.2 CORAL REEFS: ARCHIVES OF PAST SEA-LEVEL AND ENVIRONMENTAL CHANGES;423
16.6.3;3.6.3 THE LAST DEGLACIAL SEA-LEVEL RISE IN THE SOUTH PACIFIC;426
16.6.4;3.6.4 EXPEDITION 310 “TAHITI SEA LEVEL”;427
16.6.5;3.6.5 EXPEDITION 325 (GBR ENVIRONMENTAL CHANGES);444
16.6.6;3.6.6 CONCLUSIONS;453
16.6.7;REFERENCES;457
17;Chapter 4- Solid Earth Cycles andGeodynamics;468
17.1;Chapter 4.1 Introduction;470
17.1.1;Chapter 4.2.1 - Formation and Evolution of Oceanic Lithosphere: New Insights on Crustal Structure and Igneous Geochemistry from ODP/IODP Sites 1256, U1309, and U1415;474
17.1.1.1;4.2.1.1 INTRODUCTION;474
17.1.1.2;4.2.1.2 DEEP DRILLING IN SLOW-SPREAD CRUST: THE ATLANTIS MASSIF;489
17.1.1.3;4.2.1.3 DEEP DRILLING OF INTACT OCEAN CRUST FORMED AT A SUPERFAST SPREADING RATE: HOLE 1256D;502
17.1.1.4;4.2.1.4 SHALLOW DRILLING IN FAST-SPREAD LOWER CRUST AT HESS DEEP;516
17.1.1.5;4.2.1.5 CONCLUSION;518
17.1.1.6;ACKNOWLEDGMENTS;520
17.1.1.7;REFERENCES;520
17.1.2;Chapter 4.2.2 - Hydrogeologic Properties, Processes, and Alteration in the Igneous Ocean Crust;532
17.1.2.1;4.2.2.1 INTRODUCTION;532
17.1.2.2;4.2.2.2 CRUSTAL HYDROGEOLOGY AND ALTERATION;539
17.1.2.3;4.2.2.3 SYNTHESIS: METHOD AND SITE COMPARISONS AND TRENDS;558
17.1.2.4;ACKNOWLEDGMENTS;566
17.1.2.5;REFERENCES;566
17.2;Chapter 4.3 - Large-Scale and Long-Term Volcanism on Oceanic Lithosphere;578
17.2.1;4.3.1 INTRODUCTION;578
17.2.2;4.3.2 HISTORY OF DRILLING LIPS AND HOTSPOT TRAILS DURING DSDP AND ODP;582
17.2.3;4.3.3 IODP EXPEDITION 324 TO THE SHATSKY RISE;586
17.2.4;4.3.4 IODP EXPEDITION 330 TO THE LOUISVILLE SEAMOUNT TRAIL;596
17.2.5;4.3.5 OCEANIC PLATEAUS: PLUMES OR PLATE BOUNDARIES?;608
17.2.6;4.3.6 LARGE-SCALE MANTLE MOVEMENTS TRACED BY SEAMOUNT TRAILS;611
17.2.7;4.3.7 CONCLUSIONS AND FUTURE WORK;612
17.2.8;REFERENCES;614
17.3;Chapter 4.4.1 - Subduction Zones: Structure and Deformation History;624
17.3.1;4.4.1.1 INTRODUCTION;624
17.3.2;4.4.1.2 IODP DRILLING AT THREE SUBDUCTION ZONES: TARGETS AND OBJECTIVES;632
17.3.3;4.4.1.3 HIGHLIGHTS OF SCIENTIFIC RESULTS FROM IODP SUBDUCTION ZONE DRILLING;636
17.3.4;4.4.1.4 FUTURE DIRECTIONS;651
17.3.5;4.4.1.5 SUMMARY AND CONCLUSIONS;653
17.3.6;ACKNOWLEDGMENTS;654
17.3.7;REFERENCES;655
17.4;Chapter 4.4.2 - Seismogenic Processes Revealed Through the Nankai Trough Seismogenic Zone Experiments: Core, Log, Geophysics, and Observatory Measurements;666
17.4.1;4.4.2.1 INTRODUCTION;666
17.4.2;4.4.2.2 STRESS STATE AND PHYSICAL PROPERTIES IN SHALLOW FORMATIONS;667
17.4.3;4.4.2.3 FAULT ZONE STATE AND PROPERTIES;679
17.4.4;4.4.2.4 BOREHOLE OBSERVATORY;684
17.4.5;4.4.2.5 SUMMARY AND IMPLICATIONS;688
17.4.6;ACKNOWLEDGMENTS;689
17.4.7;REFERENCES;690
17.5;Chapter 4.4.3 - Fluid Origins, Thermal Regimes, and Fluid and Solute Fluxes in the Forearc of Subduction Zones;696
17.5.1;4.4.3.1 INTRODUCTION;696
17.5.2;4.4.3.2 ACCRETIONARY AND EROSIVE CONVERGENT MARGINS;701
17.5.3;4.4.3.3 GLOBAL ESTIMATES OF FLUID SOURCES AND INPUT FLUXES;703
17.5.4;4.4.3.4 FOREARC THERMAL REGIMES;706
17.5.5;4.4.3.5 FLUID OUTPUTS, FLOW RATES AND FLUXES;713
17.5.6;4.4.3.6 GLOBAL VOLATILE AND MASS CYCLING IN SZS, HAS IT EVOLVED OR FLUCTUATED THROUGH TIME?;734
17.5.7;4.4.3.7 CONCLUDING REMARKS;735
17.5.8;4.4.3.8 APPENDICES;736
17.5.9;ACKNOWLEDGMENTS;748
17.5.10;REFERENCES;748
18;Chapter 5: Appendix - One-Page Summaries of IODP Expeditions 301–348;760
19;Index;814
19.1;A;814
19.2;B;815
19.3;C;815
19.4;D;816
19.5;E;817
19.6;F;818
19.7;G;818
19.8;H;818
19.9;I;819
19.10;J;820
19.11;K;821
19.12;L;821
19.13;M;821
19.14;N;822
19.15;O;823
19.16;P;824
19.17;Q;825
19.18;R;825
19.19;S;825
19.20;T;828
19.21;U;829
19.22;V;829
19.23;W;829
19.24;X;829

Leseproben

Chapter 1

Major Scientific Achievements of the Integrated Ocean Drilling Program

Overview and Highlights

Keir Becker email address: [e-mail]     Department of Marine Geosciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Coral Gables, FL, USA

Abstract

This chapter presents scientific and programmatic highlights of the Integrated Ocean Drilling Program (IODP), including selected results during the IODP time period (2003–2013) that stemmed from drilling during the final years of the previous Ocean Drilling Program (ODP). The chapter is organized by the main themes and initiatives of the IODP Initial Science Plan (ISP), and therefore also provides an initial assessment of IODP performance in meeting the goals of the ISP. This assessment must be considered preliminary in that many of the later IODP expeditions have yet to produce their definitive results. Nevertheless, it is clear that IODP results have made significant contributions in the ISP objectives related to past greenhouse climates, rapid climate change and sea level history in the current icehouse world, subseafloor hydrogeology and biosphere, subduction zone seismogenesis, and accretion of oceanic crust formed at slow and fast spreading rates.

Keywords

Chikyu; IODP; Initial Science Plan; JOIDES Resolution; MSP; Scientific ocean drilling

1.1. Introduction

The Integrated Ocean Drilling Program (IODP, 2003–2013) was built on the rich heritage of the Ocean Drilling Program (ODP, 1983–2003) and its predecessor the Deep Sea Drilling Project (DSDP, 1968–1983) to renew and expand one of the most successful international programs in all of science. DSDP and ODP each provided access to a single scientific drillship that could be utilized by a wide community of geoscientists to address a number of important scientific problems in typesettings beneath the seafloor. With a wider international funding base, IODP provided expanded access for a larger international community to three types of scientific drilling platforms that could address an even greater range of scientifically and societally important themes beneath the seafloor. No other programs have provided such scientific access beneath nearly 70% of Earth’s surface; the result is a huge legacy of important results from scientific ocean drilling (e.g., National Research Council, 2011).

IODP was planned around an ambitious and challenging 10-year Initial Science Plan (ISP; IODP, 2001). The ISP was based partly on extending the performance and ODP legacy of the U.S.-provided riserless drillship JOIDES Resolution, with the addition of two major new elements (Figure 1.1) reflecting the unique technological capabilities of the Japanese riser drillship Chikyu and mission-specific platforms (MSPs) provided by ECORD (the European Consortium for Ocean Research Drilling). Like this entire volume, this chapter is organized in parallel with the three main themes and eight initiatives identified in the ISP, and in that sense it represents not just an overview of IODP achievements but also a broad initial assessment of the program’s success in addressing its original plan.

Figure 1.1 IODP drilling vessels, left to right: JOIDES Resolution (USIO), Vidar Viking (ECORD charter for Expedition 302), Chikyu (CDEX).

Note that IODP formally started as an international program in 2003, but IODP drilling operations did not begin until July 2004. Note also that the operating time realized for all IODP drilling vessels was considerably less than initially envisioned, mainly because of (1) shipyard delays affecting delivery of Chikyu and refitting of JOIDES Resolution and (2) a program-wide mismatch between operating expenses and financial resources. Partly because of the former, only 15 IODP expeditions were completed during the first 5 years of the program, whereas over two-thirds of all IODP expeditions were conducted between 2009 and 2013.

This chapter presents an overview and selected highlights of published results from IODP drilling, but it is not intended as a comprehensive review of all 51 IODP expeditions. As it typically takes a few years after expeditions for comprehensive scientific results to be produced, the results that have emerged to date from the last two-thirds of IODP expeditions during remain incomplete and are unavoidably underrepresented in this chapter, last revised in July 2014. Locations of the IODP expeditions and sites discussed in this chapter are shown in Figure 1.2. (Note that the Appendix, chapter 5 of this volume, includes both a map and table that include all IODP expeditions.) In most cases, later chapters in this book explore these contributions in much greater detail from the perspectives of experts in the respective subjects. While the focus here is on IODP results, it is impossible to separate the strong links to late stages of ODP. For example, 20 of the 51 IODP expeditions were based on proposals submitted originally to ODP. Also, the last 2 years of ODP drilling produced major scientific papers during the IODP era that were significant contributions toward IODP initiatives and so are included in those sections below.

Despite the underrepresentation of later IODP expeditions, it is already evident that excellent, sometimes breakthrough scientific progress was made on all three main themes and a majority of the eight initiatives identified in the ISP, and several IODP expeditions had extraordinary impact in the public media. More modest progress was made on a couple of the ISP initiatives, and for various reasons one was basically not attempted. None were completely addressed, which is not surprising given the complexity of the Earth system. In many cases, important IODP results led to identifying equally important remaining questions that provide compelling opportunities and challenges for a 10-year renewal of the program—with a different programmatic organization as the International Ocean Discovery Program. Although the post-2013 program shares the same acronym and platforms, in this chapter “IODP” is used exclusively to refer the 2003–2013 IODP.

Figure 1.2 Locations of IODP Expeditions discussed in this chapter. Color code: purple (dark gray in print versions) = deep biosphere and subseafloor ocean; yellow (white in print versions) = extreme climates and rapid climate change; orange (light gray in print versions) = sea level change; blue (black in print versions) = solid earth cycles and geodynamics. Topographic basemap produced using GeoMapApp (Ryan et al., 2009).

1.2. The Deep Biosphere and the Subseafloor Ocean (Initiatives in Deep Biosphere and Gas Hydrates)

The importance of using scientific ocean drilling to understand fluid flow and hydrology beneath the subseafloor was recognized about midway through DSDP around the time of the discovery of hydrothermal circulation in the oceanic crust. This became a strong theme during ODP, particularly in several type examples of subduction zones and thickly sedimented young oceanic crust. It also motivated development of ODP long-term “CORK” (Circulation Obviation Retrofit Kit) hydrological observatories (Becker & Davis, 2005; Davis, Becker, Pettigrew, Carson, & MacDonald, 1992) that were highlighted in the ISP as an important technological approach for IODP. The ISP theme described efforts to understand “the subseafloor ocean in various geological settings” including mid-ocean ridges, ridge flanks, old ocean basins, large igneous provinces (LIPs), subduction zones, passive margins, and carbonate platforms. IODP expanded the strong ODP efforts in ridge flank and subduction zone hydrogeology, as described in chapters by Fisher et al. (chapter 4.2.2 of this volume) and Kastner et al. (chapter 4.4 of this volume). IODP also made pioneering efforts in the overpressured Gulf of Mexico passive margin and the Okinawa Trough sediment-covered back-arc spreading center. The subduction zone contributions were largely in the context of (1) the Vancouver margin gas hydrates province described in this section under the gas hydrates initiative and (2) the Nankai Trough and Costa Rica seismogenesis programs (NanTroSEIZE and CRISP, respectively) that are described in Section 1.4 of this chapter (Solid Earth Cycles and Geodynamics).

IODP ridge flank hydrogeological contributions centered on long-term monitoring and active experiments in two classical type locations previously investigated during DSDP and ODP: the thickly sedimented eastern flank of the Juan de Fuca Ridge (Fisher, Urabe, Klaus, & the IODP Expedition 301 scientists, 2005; Fisher et al., 2012) and the isolated “North Pond” sediment pond on the western flank of the Mid-Atlantic Ridge (Edwards, Bach, Klaus, & the IODP Expedition 336 Scientists, 2014). In both cases, the IODP hydrological contributions involved dedicated long-term monitoring efforts and a focus on biosphere studies, the latter described in this section under the “Deep Biosphere” initiative (see also Orcutt and Edwards, chapter 2.5 of this volume). In both settings, ODP experiments and long-term monitoring had demonstrated that there must be very large lateral fluid fluxes in highly permeable, sediment-covered upper oceanic basement, but that very small pressure differentials were associated with the fluid fluxes (e.g., Davis & Becker, 1998; Davis, Wang, Becker, & Thomson,...