This format article was designed for Educating purpose, under the Lusi Library:Knowledge Management
Without any change in the context
This Scientific Article Was contributed by M.L. Rudolph to Hardi Prasetyo
as founded and Curator of the Lusi Library Knowledge Management
Accepted Article, © 2013 American Geophysical Union.
Evolution and future of the Lusi mud eruption
inferred from ground deformation
Evolusi dari semburan mud volcano Lusi ditentukan berdasarkan deformasi tanah
M. L. Rudolph1, M. Shirzaei1, M. Manga1, and Y. Fukushima 2
1 - Department of Earth and Planetary Science, University of California, Berkeley, California, USA.
2 - Disaster Prevention Research Institute, Kyoto University, Uji Prefecture, Japan
Original Article:
Modified Figures Captions:
Tinjauan cepat Makalah Ilmiah ke dalam bahasa Indonesia
oleh Hardi Prasetyo untuk LUSI LIBRARY: KNOWLEDGE MANGEMENT.
Dokumen ini juga memperkuat fakta, bahwa Lusi mud volcano sebagai suatu keajaiban dunia (th
e World Wonder).
Masih penuh diselubungi misteri alam terkait asal usulnya, dan memperkuat kondisi bahwa Lusi sebagai pusat keunggulan untuk studi fenomena mud volcano di Indonesia dan dunia.
Sari
Figure 2. Results of principle component analysis of ground deformation data. (a) Spatial pattern associated with first principal component. Data has been projected onto a regular grid for visualization. White dashed line indicates boundary between West (well) and East (Lusi) regions. (b) Temporal weighting coefficient (black) and a best fit exponential curve (red) for East region. (c) same as (b) for West region. Both positive and negative values are expected because the deformation described by PCAis measured relative to the temporal mean displacement.
Peluang emas mempelajari semburan Lusi mud volcano:
Semburan gunung lumpur Lusi (Lusi mud volcano) di Jawa Timur, Indonesia yang sampai saat ini masih berlangsung, menyediakan suatu kesempatan yang belum pernah terjadi sebelumnya.
Untuk mempelajari suatu semburan berukuran besar, mulai dari saat awal kejadiannya sampai pada akhir kehidupannya.
Pengamatan deformasi tanah baru, menunjukkan semburan Lusi akan berhenti lebih cepat dari perkiraan sebelumnya
Penulis telah menggunakan pengamatan deformasi tanah yang baru, diperoleh dari hasil analisis interferometrik multitemporal dari L-band data synthetic aperture radar (SAR).
Untuk menunjukkan bahwa Lusi akan berhenti menyembur lebih cepat daripada perkiraan yang telah dihasilkan sebelumnya.
Debit semburan akan menurun menjadi tingkat 10% dari tingkat selama 5 tahun belakangan ini
Analisis dengan menggunakan komponen utama, telah ditemukan bahwa laju deformasi tanah, dan dengan implikasi, tekanan di daerah sumber lumpur, telah berkurang secara eksponensial dengan skala bebara kali lipat dari ± 21,04 tahun.
Kami memperkirakan bahwa debit yang akan menurun menjadi 10% dari tingkat yang terjadi selama 5 tahun kebelakang
(We anticipate that discharge will decrease to 10% of the present rate in 5 years).
4. Diskusi
Figure 3. Discharge measured at Lusi from December 2006 on wards [13,14,15]. Vertical bars indicate the range of reported values. The precise date on which discharge measurements were made are not always reported and horizontal bars indicate the approximate time period in which each discharge measurement was made. The red solid line is the best fit to the discharge measurements and the dashed lines show the 95% confidence interval for this fit.
Perkiraan panjang umur semburan sebelumnya didasarkan pada perkiraan debit lumpur dan beberapa konsepsi model semburan
Usaha-usaha sebelumnya untuk memperkirakan panjang umur dari semburan Lusi (estimate the longevity of the Lusi eruption) telah mengandalkan secara signifikan pada perkiraan debit lumpur (estimates of mud discharge) dikombinasikan dengan beberapa model konseptual untuk mekanisme semburan (differing conceptual models for the mechanics of the eruption).
Volume semburan diperkirakan dari ketebalan batuan sumber dan cakupan sebarannya
Volume semburan lumpur (The volume of erupted mud) diperkirakan dari survei lapangan rinci terhadap aliran sedimen (deposit thickness).
Dikombinasikan dengan perkiraan daerah tergenang (estimates of inundated area) berdasarkan foto satelit [11].
Ketebalan sumber lumpur dibagi volume lumpur didapatkan perkiraan konservatif panjang umur 25-35 tahun.
Menggunakan perkiraan ketebalan sumber lumpur (mud source thickness) dan luasnya udara yang berasal dari profil seismik refleksi dan survei gravitasi (aerial extent derived from seismic reflection profiles and gravity surveys), [11] memperoleh perkiraan konservatif umur panjang (conservative estimate of longevity) (23-35 tahun) dengan membagi volume lumpur yang tersedia dengan debit volumetrik (available volume of mud by the volumetric discharge).
Perkiraan panjang umur tidak membuat asumsi tentang mekanisme semburan
Sedangkan perkiraan umur panjang [11] tidak membuat asumsi tentang mekanisme semburan (no assumptions about the mechanics of the eruption), perkiraan berikutnya telah diandalkan model mekanik letusan (mechanical models of the eruption) [6,17].
Salah satu model bahwa semburan berlanjut oleh adanya akuifer karbonat dalam
Dengan mengambil pendekatan Monte-Carlo untuk mengeksplorasi pengaruh parameter model yang tidak diketahui, perkiraan umur panjang probabilistik
(probabilistic longevity estimates) dapat dihasilkan dari model mekanis tersebut. [6] diasumsikan bahwa semburan berlanjut oleh adanya overpressure dari akuifer karbonat yang dalam (assumed that the eruption is sustained by overpressure in a deep carbonate aquifer
Air naik keatas dari akuifer ini dan membawa lumpur pada tingkat yang sebanding dengan debit air (
Satu model perhitungan panjang umur 26 tahun
Menggunakan model konseptual, perkiraan panjang umur 50 persentil adalah 26 tahun [6]. [17] mengusulkan sebuah model konseptual yang berbeda untuk semburan (conceptual model for the eruption).
Menggunakan model konseptual ini, Pada Rudolph: 2011kv menggunakan distribusi probabilitas yang berbeda untuk parameter model yang tidak diketahui, diperoleh perkiraan panjang umur 50 persentil dengan antara 25-50 tahun
Bukti baru laju deformasi tanah benurun seiring perjalanan waktu
Berdasarkan evolusi koefisien amplitudo dari temporal komponen utama pertama deformasi tanah (the evolution of the temporal amplitude coefficient of the first principal component of the ground deformation) (Gambar 2), kami menyimpulkan bahwa laju deformasi tanah menurun terhadap waktu (the rate of ground deformation is decreasing in time) .
Kaitan semburan, deformasi di permukaan dan tekanan dalam ruang lumpur di bawah permukaan
Jika lumpur yang disemburkan dari sebuah ruang dengan batas-batas spasial yang tetap dan sekitarnya elastis (a chamber with fixed spatial boundaries and elastic surroundings), deformasi di permukaan linier sebanding dengan perubahan tekanan dalam ruang lumpur (surface deformation is linearly proportional to the change in pressure within the mud chamber).
Berdasarkan asumsi ini, evolusi dari koefisien amplitudo temporal (the evolution of the temporal amplitude coefficient) dapat digunakan secara langsung sebagai pendekatan untuk evolusi tekanan pada sumber lumpur (as a proxy for the evolution of pressure in the mud source), dan skala waktu peluruhan eksponensial dari deformasi tanah (the exponential decay time scale of the ground deformation) (21 ± 04 tahun Adalah sama dengan peluruhan eksponensial skala waktu tekanan di daerah sumber lumpur (the exponential decay time scale of pressure in the mud source region).
Peluruhan (penurunan) eksponensial skala waktu dari deformasi versus debit semburan
Karena debit adalah berbanding lurus dengan pengendali gradien tekanan (the driving pressure gradient), sedangkan saluran geometri dan reologi lumpur adalah konstan, kita dapat menggunakan peluruhan eksponensial skala waktu terkait dengan deformasi tanah langsung sebagai pendekatan untuk peluruhan eksponensial skala waktu dari debit (the exponential decay time scale associated with ground deformation directly as a proxy for the exponential decay timescale of discharge) .
Aliran dari ruang lumpur yang overpressured (Discharge from an overpressured mud chamber) dengan lingkungan yang elastis diharapkan secara eksponensial menurun, sebagai hasil yang berlaku terlepas dari apakah larutan padat volatil terjadi pada sumber lumpur [20].
Perubahan debit semburan 2006-2012
Aliran Lusi (Discharge from Lusi) adalah sebesar 100.000m3/hari pada akhir tahun 2006 [13] dan kemudian menurun menjadi 10.000m3/hari[15].
Perkiraan semburan pada tahun 2017 <10.000m3
Karena semburan berlanjut, tekanan elastis dihasilkan sebagai respon dari penarikan lumpur dari kedalaman akan terus meningkat, dan tekanan ini masih bisa menjadi cukup besar untuk memobilisasi lumpur tambahan [17] atau untuk menyebabkankaldera terbentuk (a caldera to form).
Skenario terbentuknya kaldera
Sebaliknya, tekanan akan dihalangi oleh penutup (overburden) kaldera (
1. Pendahuluan
Lusi peluang emas mempelajari semburan mud volcano yang besar sejak kelahirannya
Semburan yang masih berlangsung dari gunung lumpur Lusi (Lusi mud volcano), Jawa Timur, Indonesia (Gambar 1) menawarkan kesempatan belum pernah terjadi sebelumnya untuk mempelajari semburan yang besar dari awal sampai masa akhirnya nya (
Dampak semburan Lusi pada sendi-sendi kehidupan masyarakat
Semburan ini telah menimbulkan kerusakan pada masyarakat lokal, mengungsikan lebih dari 60.000 orang dan menyebabkan kerugian ekonomi > 4 $Milyar [16].
Meskipun upaya yang signifikan untuk memahami dan memprediksi panjang umur semburan [11,6,17,15], evolusi spatiotemporal dari sumber pasokan dari semburan belum dipahami dengan baik (
Pengamatan baru menunjukkan bahwa semburan lusi akan lebih cepat dari perkiraan sebelumnya
Kami menyajikan pengamatan baru deformasi tanah (
Perkiraan umur semburan sebelumnya 23-50 tahun berdasarkan perkiraan debit 3 tahun pertama
Penilaian sebelumnya bahaya yang ditimbulkan (
Selama ini fenomena deformasi tanah belum digunakan untuk memperkirakan panjang umur semburan
Meskipun deformasi tanah dekat Lusi telah digunakan sebelumnya untuk mengkarakterisasi pola spasial dan laju amblesan (the spatial pattern and rate of subsidence) [1] dan untuk mempelajari sumber dari deformasi tanah selama tahun pertama dari semburan [10], namun deformasi tanah belum digunakan secara langsung untuk memperkirakan panjang umur semburan (to estimate the longevity of the eruption).
Deformasi tanah akan menurun secara eksponensial dan debit akan menurun pada 5 tahun menjadi 10% dari kecepatan yang sekarang
Kami menemukan bahwa laju deformasi tanah, dan dengan inferensi, tekanan di daerah sumber lumpur (pressure in the mud
2. Methods
We list the dates of acquisition in Table 1. To generate a time series of the surface deformation field over Lusi, we employ a multiple-master SAR interferometry approach [18]. Given 21 and 25 SAR scenes acquired in descending orbit mode (azimuth = 188 and incidence angle 34.3) from paths 91 and 92, respectively, we generated 400 interferograms.
We provide examples of four interferograms in Supplementary Figure 1. The geometrical phase is estimated and subtracted using satellite precise ephemeris data and a reference SRTM digital elevation model of 90 m resolution [8,9].
To obtain an unambiguous phase observation from modulo 2p phase change measured in each interferogram, we use a model-assisted approach [2] combined with a 2D phase unwrapping operator [4] and apply it to high quality pixels in the image [5].
The algorithm for identifying high quality pixels is based on estimated phase noise [18].
Then, each data set is inverted using a linear unbiased estimation approach [3] to generate the time series of the displacement field.
We note that through this procedure very localized and rapid deformation components may be lost, but the general trend due to mud source deformation, the subject of this study, is preserved.
By applying a temporal high pass and spatial low pass filter we reduce the effect of atmospheric delay on the displacement time series [18].
The cumulative displacements during the period of study are shown as contours in Figure 1 and we show the intermediate displacements in Supplementary Figure 2. Time series of displacements at several locations are shown in Supplementary Figure 3.
3. Results
The spatial modes associated with the first principal components for both West and East regions are shown in Figure 2a.
The first principal component for the West region accounts for 90% of the variance in the displacement dataset and in the East region, the first principal component explains 93% of the variance.
In Figure 2b-c, we show the temporal amplitude coefficient for the first principal component for the East and West regions.
The temporal amplitude coefficient for each region is well-approximated by an exponential function of time of the form y=a exp(-t/b), where t is time.
We fit exponential functions of this form to the temporal amplitude coefficient in both East and West regions and recover b-values of 21 04.± . and 40 14. ±. years with 2 R values of 0.98 and 0.97, respectively.
Including additional exponential terms did not significantly improve the quality of the fit.
The orientation and horizontal position of the line separating the East and West regions affects the recovered b value for the East region by less than 10%, indicating that our results are not contingent upon the precise choice of the boundary between the regions containing the well and Lusi.
The higher principal components (Supplementary Figure 4) contain no obvious signal.
FIGURES AND TABLE
Table 1. Acquisition dates, paths, and frames corresponding to the ALOS PALSAR data used in our
study.
Figure 1. (a) Regional map showing Lusi’s location (indicated by red star) in East Java. (b) Contour plot of cumulative vertical displacement showing subsidence due to Lusi and a nearby well between October, 2006 and April, 2011 superimposed on a satellite photo of the affected area.
Figure 2. Results of principle component analysis of ground deformation data. (a) Spatial pattern associated with first principal component. Data has been projected onto a regular grid for visualization. White dashed line indicates boundary between West (well) and East (Lusi) regions. (b) Temporal weighting coefficient (black) and a best fit exponential curve (red) for East region. (c) same as (b) for West region. Both positive and negative values are expected because the deformation described by PCAis measured relative to the temporal mean displacement.
Figure 3. Discharge measured at Lusi from December 2006 on wards [13,14,15]. Vertical bars indicate the range of reported values. The precise date on which discharge measurements were made are not always reported and horizontal bars indicate the approximate time period in which each discharge measurement was made. The red solid line is the best fit to the discharge measurements and the dashed lines show the 95% confidence interval for this fit.
Abstract
The ongoing eruption of the Lusi mud volcano in East Java, Indonesia offers the unprecedented opportunity to study a large eruption from its beginning to its eventual end.
We use new observations of ground deformation obtained from multitemporal interferometric analysis of L-band synthetic aperture radar data to show that Lusi will stop erupting much sooner than previously anticipated.
Using principal component analysis, we find that the rate of ground deformation, and by implication, pressure in the mud source region, has been decaying exponentially with an e-folding time scale of 21 04.± years. We anticipate that discharge will decrease to 10% of the present rate in 5 years.
1. Introduction
The ongoing eruption of the Lusi mud volcano, East Java, Indonesia (Figure 1) offers the unprecedented opportunity to study a large eruption from its beginning to its eventual end.
This eruption has devastated local communities, displacing more than 60,000 people and causing > $4B in economic losses [16].
Despite significant efforts to understand the eruption and predict its longevity [11,6,17,15], the spatiotemporal evolution of the source feeding the eruption is not well understood.
We present new observations of ground deformation that indicate that Lusi will stop erupting much sooner than previously anticipated [11,6,17].
Previous assessments of the hazard posed by Lusi relied upon estimates of discharge during the first three years of the eruption [13,19,11], concluding that the eruption will last 23-50 years [11,6,17].
Although ground deformation near Lusi has been used previously to characterize the spatial pattern and rate of subsidence [1] and to study the source of the ground deformation during the first year of the eruption [10], ground deformation has not been used directly to estimate the longevity of the eruption.
We find that the rate of ground deformation, and by inference, pressure in the mud
source region, is decreasing exponentially and that discharge will decrease to 10% of the present rate in 5 years.
4. Discussion
Previous attempts to estimate the longevity of the Lusi eruption have relied significantly upon estimates of mud discharge combined with differing conceptual models for the mechanics of the eruption.
The volume of erupted mud was estimated from detailed field surveys of deposit thickness combined with estimates of inundated area based on satellite photographs [11].
Using estimates of mud source thickness and aerial extent derived from seismic reflection profiles and gravity surveys, [11] obtained a conservative estimate of longevity (23-35 years) by dividing the available volume of mud by the volumetric discharge.
While the longevity estimate of [11] made no assumptions about the mechanics of the eruption, subsequent estimates have relied upon mechanical models of the eruption [6,17].
By taking the Monte-Carlo approach to explore the influence of unknown model parameters, probabilistic longevity estimates can be generated from such mechanical models. [6] assumed that the eruption is sustained by overpressure in a deep carbonate aquifer.
Water ascends from this aquifer and entrains mud at a rate proportional to the water discharge.
Using this conceptual model, the 50th percentile longevity estimate is 26 years [6]. [17] proposed a different conceptual model for the eruption in which the eruption is driven by overpressure in the mud source region and gas exsolution and expansion, and the mud source expands during the eruption as mud is progressively mobilized.
Using this conceptual model, it et Rudolph: 2011kv obtained 50th percentile longevity estimates between 25-50 years using different probability distributions for the unknown model parameters.
Based on the evolution of the temporal amplitude coefficient of the first principal component of the ground deformation (Figure 2), we conclude that the rate of ground deformation is decreasing in time.
If the mud is erupting from a chamber with fixed spatial boundaries and elastic surroundings, surface deformation is linearly proportional to the change in pressure within the mud chamber.
Under these assumptions, the evolution of the temporal amplitude coefficient can be used directly asa proxy for the evolution of pressure in the mud source, and the exponential decay time scale of the ground deformation ( 21 04.± years) is the same as the exponential decay time scale of pressure in the mud source region.
Because discharge is linearly proportional to the driving pressure gradient when conduit geometry and mud rheology are constant, we can use the exponential decay timescale associated with ground deformation directly as a proxy for the exponential decay timescale of discharge.
Discharge from an overpressured mud chamber with elastic surroundings is expected to decrease exponentially, a result that holds true regardless of whether volatile exsolution occurs in the mud source [20].
Discharge from Lusi was 10 m5 m3/day in late 2006 [13] and has subsequently decreased to 104 m3/day [15].
We plot discharge measurements together with an exponential fit to the discharge measurements of the form y=a exp(-t/b) in Figure 3. The e-folding time b recovered by fitting the discharge measurements is 12 08.± years.
The reported uncertainty should be viewed as a lower bound as the methodology, timing, and uncertainty associated with the discharge measurements are not documented in the literature.
Thus, we find that the evolution of the eruption inferred from discharge measurements is consistent with (though less certain than) our geodetic observations.
Assuming that the same behavior of the eruption over the last six years continues (e.g. no caldera forms and the mud chamber and conduit geometry do not change), we expect that the discharge at Lusi will decrease by an order of magnitude to < 103 m3/day by 2017 1± year.
As the eruption proceeds, elastic stresses generated in response to the withdrawal of mud from depth will continue to increase, and these stresses could still become sufficiently large to mobilize additional mud [17] or to cause a caldera to form.
If a caldera forms, pressure in the mud source region is no longer expected to decrease exponentially in time.
Rather, pressure will be buffered by the overburden of the caldera’s , which will be coupled to its surroundings by friction on Caldera-bounding faults.
If there is an external fluid reservoir involved in the eruption [6,15], our longevity assessment is unaffected because the surface deformations result from withdrawal of mud that becomes entrained in the erupting water, and the entrainment rate is related to the discharge from (and overpressure in) the hypothetical external fluid reservoir, in which pressure is expected to decrease exponentially in time. dalam) fluida reservoir eksternal hipotetik, di mana tekanan diperkirakan menurun secara eksponensial terhadap waktu (pressure is expected to decrease exponentially in time)
4. Discussion
Previous attempts to estimate the longevity of the Lusi eruption have relied significantly upon estimates of mud discharge combined with differing conceptual models for the mechanics of the eruption.
The volume of erupted mud was estimated from detailed field surveys of deposit thickness combined with estimates of inundated area based on satellite photographs [11].
Using estimates of mud source thickness and aerial extent derived from seismic reflection profiles and gravity surveys, [11] obtained a conservative estimate of longevity (23-35 years) by dividing the available volume of mud by the volumetric discharge.
While the longevity estimate of [11] made no assumptions about the mechanics of the eruption, subsequent estimates have relied upon mechanical models of the eruption [6,17].
By taking the Monte-Carlo approach to explore the influence of unknown model parameters, probabilistic longevity estimates can be generated from such mechanical models. [6] assumed that the eruption is sustained by overpressure in a deep carbonate aquifer.
Water ascends from this aquifer and entrains mud at a rate proportional to the water discharge.
Using this conceptual model, the 50th percentile longevity estimate is 26 years [6]. [17] proposed a different conceptual model for the eruption in which the eruption is driven by overpressure in the mud source region and gas exsolution and expansion, and the mud source expands during the eruption as mud is progressively mobilized.
Using this conceptual model, it et Rudolph: 2011kv obtained 50th percentile longevity estimates between 25-50 years using different probability distributions for the unknown model parameters.
Based on the evolution of the temporal amplitude coefficient of the first principal component of the ground deformation (Figure 2), we conclude that the rate of ground deformation is decreasing in time.
If the mud is erupting from a chamber with fixed spatial boundaries and elastic surroundings, surface deformation is linearly proportional to the change in pressure within the mud chamber.
Under these assumptions, the evolution of the temporal amplitude coefficient can be used directly asa proxy for the evolution of pressure in the mud source, and the exponential decay time scale of the ground deformation ( 21 04.± years) is the same as the exponential decay time scale of pressure in the mud source region.
Because discharge is linearly proportional to the driving pressure gradient when conduit geometry and mud rheology are constant, we can use the exponential decay timescale associated with ground deformation directly as a proxy for the exponential decay timescale of discharge.
Discharge from an overpressured mud chamber with elastic surroundings is expected to decrease exponentially, a result that holds true regardless of whether volatile exsolution occurs in the mud source [20].
Discharge from Lusi was 10 m5 m3/day in late 2006 [13] and has subsequently decreased to 104 m3/day [15].
We plot discharge measurements together with an exponential fit to the discharge measurements of the form y=a exp(-t/b) in Figure 3. The e-folding time b recovered by fitting the discharge measurements is 12 08.± years.
The reported uncertainty should be viewed as a lower bound as the methodology, timing, and uncertainty associated with the discharge measurements are not documented in the literature.
Thus, we find that the evolution of the eruption inferred from discharge measurements is consistent with (though less certain than) our geodetic observations.
Assuming that the same behavior of the eruption over the last six years continues (e.g. no caldera forms and the mud chamber and conduit geometry do not change), we expect that the discharge at Lusi will decrease by an order of magnitude to < 103 m3/day by 2017 1± year.
As the eruption proceeds, elastic stresses generated in response to the withdrawal of mud from depth will continue to increase, and these stresses could still become sufficiently large to mobilize additional mud [17] or to cause a caldera to form.
If a caldera forms, pressure in the mud source region is no longer expected to decrease exponentially in time.
Rather, pressure will be buffered by the overburden of the caldera’s , which will be coupled to its surroundings by friction on Caldera-bounding faults.
If there is an external fluid reservoir involved in the eruption [6,15], our longevity assessment is unaffected because the surface deformations result from withdrawal of mud that becomes entrained in the erupting water, and the entrainment rate is related to the discharge from (and overpressure in) the hypothetical external fluid reservoir, in which pressure is expected to decrease exponentially in time. dalam) fluida reservoir eksternal hipotetik, di mana tekanan diperkirakan menurun secara eksponensial terhadap waktu (pressure is expected to decrease exponentially in time)
Acknowledgements
This work was supported in part by funding from the National Science Foundation.
References
[1] Abidin, H. Z., R. Davies, M. Kusuma, H. Andreas, and T. Deguchi, Subsidence and uplift of Sidoarjo (East Java) due to the eruption of the Lusi mud volcano (2006-present), Environmental Geology, 2008.
[2] Bathke, H., M. Shirzaei, and T. R. Walter, Inflation and deflation at the steep-sided Llaima stratovolcano (Chile) detected by using InSAR, Geophys. Res. Lett, 38(10), L10,304,
2011.
[3] Bjerhammar, A., Bjerhammar (1973) Theory of errors and generalized matrix inverses, Elsevier, Amsterdam, 1973.
[4] Chen, C. W., and H. A. Zebker, Two-dimensional phase unwrapping with use ofstatistical models for cost functions in nonlinear optimization, Journal of the Optical Society of America A: Optics, 18(2), 338–351, 2001.
[5] Costantini, M., and P. A. Rosen, A generalized phase unwrapping approach for sparse data, inProceedings IEEE 1999 International Geoscience and Remote Sensing Symposium, pp. 267–269, IEEE, 1999.
[6] Davies, R. J., S. Mathias, R. E. Swarbrick, and M. Tingay, Probabilistic longevity estimate for the LUSI mud volcano, East Java, Journal of the Geological Society, 168(2), 517–523, 2011.
[7] Eckart, C., and G. Young, The approximation of one matrix by another of lower rank,Psychometrika, 1(3), 211–218, 1936.
[8] Farr, T. G., P. A. Rosen, E. Caro, R. Crippen, R. Duren, S. Hensley, M. Kobrick,M. Paller, E. Rodriguez, L. Roth, D. Seal, S. Shaffer, J. Shimada, J. Umland, M. Werner, M. Oskin, D. Burbank, and D. Alsdorf, The Shuttle Radar Topography Mission, Rev. Geophys., 45(2), 2007.
[9] Franceschetti, G., Synthetic aperture radar processing, CRC Press, Boca Raton, 1999.
[10] Fukushima, Y., J. Mori, M. Hashimoto, and Y. Kano, Subsidence associated with the LUSI mud eruption, East Java, investigated by SAR interferometry, Marine and Petroleum Geology,26(9), 1740–1750, 2009.
[11] Istadi, B., G. Pramono, and P. Sumintadireja, Modeling study of growth and potential geohazard for LUSI mud volcano: East Java, Indonesia, Marine and Petroleum Geology, 26, 1724–1739, 2009.
[12] Jolliffe, I., Principal Component Analysis, Springer-Verlag, 1986. [13] Mazzini, A., H. Svensen, G. Akhmanov, G. Aloisi, S. Planke, A. Malthe-Sørenssen, and B. Istadi, Triggering and dynamic evolution of Lusi mud volcano, Indonesia, Earth and Planetary Science Letters, 261, 375–388, 2007.
[14] Mazzini, A., A. Nermoen, M. Krotkiewski, Y. Podladchikov, S. Planke, and H. Svensen, Strike-slip faulting as a trigger mechanism for overpressure release through piercement structures. Implications for the Lusi mud volcano, Indonesia, Marine and Petroleum Geology,26(9), 1751–1765, 2009.
[15] Mazzini, A., G. Etiope, and H. Svensen, A new hydrothermal scenario for the 2006 Lusi eruption, Indonesia. Insights from gas geochemistry, Earth and Planetary Science Letters, 317–318(0), 305–318, 2012.
[16] Richards, J. R., Report into the Past, Present, and Future Social Impacts of Lumpur Sidoarjo,Tech. rep., Humanitus Sidoarjo Fund, 2011.
[17] Rudolph, M. L., L. Karlstrom, and M. Manga, A prediction of the longevity of the Lusi mud eruption, Indonesia, Earth and Planetary Science Letters, 308(1-2), 124–130, 2011.
[18] Shirzaei, M., A Wavelet-Based Multitemporal DInSAR Algorithm for Monitoring Ground Surface Motion, IEEE Geoscience and Remote Sensing Letters, PP(99), 1–5, 2012.
[19] Tingay, M., O. Heidbach, R. Davies, and R. Swarbrick, Triggering of the Lusi mud eruption: Earthquake versus drilling initiation, Geology, 36(8), 639–642, 2008.