No abstract

We present analysis of the December 2018 Anak Krakatau tsunami in Sunda Strait, Indonesia, from a combination of post-tsunami field surveys, bathymetric changes and spectral analysis of the tsunami tide gauge records. Post-tsunami surveys revealed moderate tsunami height along the coast of Sumatra and Java with maximum surveyed runup of 13.5 m and maximum inundation distance of 330 m. At small islands located close to the volcano, extreme tsunami impacts were observed indicating not only a huge tsunami was generated by large amounts of collapse material which caused notable changes of seafloor bathymetry, but also indicates the role of those small islands in reducing tsunami height that propagated to the mainland of Indonesia. Our spectral analysis of tide gauge records showed that the tsunami's dominant period was 6.6-7.4 min, indicating the short-period nature of the 2018 Sunda Strait tsunami.

Ocean Thermal Energy Conversion (OTEC) adalah salah satu dari banyak sumber energi terbarukan dari lautan yang bisa menjadi solusi untuk energi hijau. Selat Makassar merupakan salah satu wilayah perairan yang sangat berpotensi untuk pembangkit OTEC. Hal tersebut karena Selat Makassar memenuhi kaidah OTEC, dimana termasuk kategori laut dalam dan berada di equator yang memiliki suhu permukaan yang hangat dan konstan, serta memiliki selisih suhu sebesar 20℃ antara permukaan laut dan laut dalam dengan kedalaman 1000 m. Tujuan dari penelitian ini adalah untuk mengetahui potensi energi OTEC, titik potensial instalasi pembangkit OTEC, dan daya yang dihasilkan di perairan Selat Makassar Utara. Analisa data menggunakan verifikasi metode Root Mean Square Error (RMSE) dan efisiensi OTEC dihitung melalui persaman efisiensi carnot. Besar daya OTEC dihitung dengan asumsi pembangkit OTEC 100 MW menghasilkan Pg (daya kotor) dan Pnet (daya bersih). Hasil penelitian menunjukkan Selat Makassar memiliki potensi energi OTEC terutama pada stasiun 2 hingga stasiun 17 dengan rata-rata selisih temperatur 23,57℃ serta efisiensi carnot rata-rata sebesar 7,7%. Menghasilkan rata-rata daya kotor sebesar 177,66 MW dan daya bersih sebesar 13,85 MW. Titik lokasi yang berpotensi dalam instalasi pembangkit OTEC berada di stasiun 2 dengan koordinat 01°01'51"N-120°13'21"E berupa platform pembangkit floating plants. Jarak dari pantai sepanjang 18,63 km. Memiliki selisih temperatur laut permukaan dan laut dalam 23,3℃ serta efisiensi carnot sebesar 7,7% sehingga menghasilkan daya bersih 13,40 MW.

The transfer of the State Capital (KN) from Jakarta to East Kalimantan Province in North Penajam Paser Regency has now been determined by the government with the enactment of Law No. 3 of 2022 concerning the State Capital. In the law, it is explained that one of the functions of IKN is as a Center of gravity (CoG), namely symbolizing the sovereignty of a country, therefore IKN is a national vital object to maintain its existence from threats, therefore IKN requires a system and strategy to protect it in this case. non-military threat. In this thesis the researcher used a descriptive qualitative research method with the formulation of the problem from the problem statement to be able to protect the IKN from non-military threats in the Indonesian Archipelagic Sea Lanes (ALKI) II. The results of the research that the researchers got were the significance of non-military threats in the inland waters defense area in ALKI II, giving rise to an urgency to develop a new IKN defense strategy that can ward off non-military threats in the planning stages of the IKN transfer. Which then the researcher concluded that in efforts to move the IKN it is important to analyze the defense of inland waters in ALKI II with the aim of maintaining the defense of IKN with an inland waters defense strategy, in order to realize national defense from non-military threats.